the john and helen glessner family trust. supporting trustworthy journalism that informs and spires. sue and edgar wachenheim, iii. corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we are your retirement company. additional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. ank you. from the tisch wnet studios at lincoln center in new york, hari sreenivasan. >> sreenivasan: good evening and thanks for joining us. the migrant flow to and through europe is slowing down as countries along the route harden their borders. austria said today it would deploy soldiers along its border with italy to block migrants who've crossed the mediterranean sea from northern africa. germany says due to tightened borders, new arrivals through austria dropped to 5,000 migrants last month, down from 65,000 in january. in greece, several dozen syrian refugees blocked a highway to protest the closed border into neighboring macedonia. 45,000 migrants and refugees are stranded in camps in mainland greece with another 5,000 on the greek islands. turkey stopped 200 migrants today from riding makeshift boats from its west coast across the aegean sea to greece. beginning monday, the 28-nation european union will deport migrants in greece to turkey, starting with those who arrived after the march 20th cutoff. the e.u.'s frontex agency is sending 1,500 police officers to assist this process. in exchange for receiving returning refugees and slowing their flow to europe, turkey has been promised economic aid and possible admission to the e.u. police in india are detaining eight employees with the construction company responsible for building the elevated roadway that collapsed on thursday in kolkata, formerly known as calcutta. after two more bodies were pulled from the wreckage today, authorities said 26 people died when the 328-foot long overpass fell. 100 people have been rescued, though no more survivors are expected to be found. indian prosecutors say the construction company employees, some of whom appeared in court today, could face charges as serious as murder and face up to life imprisonment or the death penalty. u.s. presidential candidates are focusing this weekend in wisconsin, which holds the next pivotal primary on tuesday. the republican winner will claim most of the 42 delegates at stake. billionaire businessman donald trump, who leads the republican delegate count, told supporters today, if elected, he has enough money to forgo the president's $400,000 a year salary. ohio governor john kasich said he hopes to emerge as the nominee at a contested convention in july and is not interested in running for vice president. texas senator ted cruz delivered the keynote speech today at north dakota's state convention, where 25 delegates will be chosen tomorrow. vermont senator bernie sanders today urged supporters to deliver a large turnout tuesday. sanders and hillary clinton, competing for 96 democratic delegates in wisconsin, are attending the state democratic party dinner tonight. stay on top of all of today's headlines by following us on twitter. connect with us at @newshour. >> sreenivasan: violence in iraq killed more than 1,000 people this past month, more than half of whom were civilians, according to the united nations. this rise in casualties resulted in part from terrorist attacks in the baghdad area carried out by the islamic state group, or isis. at the same time, after a week of protests, iraq's parliament has a week to confirm new members proposed to shakeup the prime minister's cabinet. a shiite muslim cleric whose militia repeatedly battled american soldiers during the u.s. war a decade ago has emerged as a key player in this political process. that cleric is muqtada al-sadr, and one of the journalists who has written about his re- emergence is "washington post" reporter liz sly, who joins me by skype from baghdad. liz, this is interesting. he took several years off from really the public scene, and this is a very public comeback. >> reporter: yes, that's right. he's been gone from politics basically for about eight years. his policy has been participating in elections in the government holding ministries, but he's been completely absent. and suddenly he's back. >> sreenivasan: describe that scene. you tell it in your story. it's him and a group of aides almost storming the fortress, if you will. >> reporter: well, yes, it was a very sort of sack ficialg lamb moment, if you like. he had threatened to send his supporters into the green zone, effectively to topple the government themselveses if they did not change the government, if the prime minister did not fire the ministers. instead when the day came everybody was really nervous that there would be violence and bloodshed in the green zone. he announced that he, himself, would go in alone and take the burden on his shoulders. he sort of ambled into the green zone, went past the checkpoint which are there to keep people out. and it was really quite an extraordinary scene because the soldiers embraced him, and the commander who is in charge of the green zone, a very top general, knelt on the floor and kissed his hands. >> sreenivasan: i was going to say, someone who can get a general to get down on a knee and kiss your hand, that is a tremendous symbolic gesture of power. what does that do to the politicians who are witnessing this? >> reporter: well, yes, it certainly did shake them up. it certainly shook up the prime minister. muqtada al-sadr set up a tent justed in the green zone. he moved into the tent. he announced he would stay there until the government was formed. he spent about five days there while everybody scrambled around, hurry, to come up with listes of new names, and when they did come up with the names, they didn't actually vote on them. he announced it was enough for him to leave and the tension abated and he did leave the green zone at that point. >> sreenivasan: this is somebody-- we talked about him 10 years ago-- muqtada al-sadr in the mahdi army. what's the state of militia-like support that he has today? >> reporter: well, yes, there's hardly a politician in the country, except the prime minister, who doesn't have a private militia. one newspaper hailed him as the gandhi of iraq for walking into the green zone like this, without arms, without weapons to make this stand. certainly the message was if you don't change the government, i've got a private army behind me and i can really shake this up. >> sreenivasan: what is the end goal? what does muqtada al-sadr want in the political process? >> ostensibly on the surface it was changing corrupt ministers? there is elections in iraq in two years' time. the results of the fight against isis has been wrath eclipsed by some other militias, and i think in two years' time, he might have lost quite a lot of votes to some of those other militias. some people are putting this into the context of a bit of early election campaigning. >> sreenivasan: liz sly from "washington post" joining us live from baghdad, thank you. >> sreenivasan: the fbi tells the newshour it is not sharing with state and local law enforcement the now-classified method it used to figure out the pin code to the apple iphone belonging to syed farook. farook was one of the two isis- inspired terrorists who shot and killed 14 people at an office party last december in san bernardino, california. the clarification comes after fbi assistant director kerry sleeper emailed police and sheriff organizations around the country yesterday, offering the agency's help going forward in the struggle to access evidence in encrypted smartphones. the fbi told us it already helps state and local authorities who have a warrant to extract data lawfully from smartphones or when the phones are damaged. earlier this week, the fbi revealed it had unlocked the san bernardino iphone without apple's help. the company had refused a court order to aid the fbi, mainly over being forced to write new software code to circumvent the privacy promised to all of its customers. this tension between the privacy protections built into today's technology and the needs of law enforcement to access information is not only a debate in federal terrorism investigations. as newshour special correspondent john larson reports in tonight's signature segment, the debate is playing out frequently over crimes being investigated at the local level. >> reporter: this heartfelt, urgent text was the last one barbara mills ever received from her daughter, brittney. it was april 24th of last year. >> she said i have you and i'm grateful. you know that i love you so much, and i don't know where i would be without you. >> reporter: hours later, at half past ten at night, someone knocked at brittney's apartment in baton rouge, louisiana, and killed her. >> it's like, has this really happened? and why? >> reporter: police believe brittney willingly opened the door. another tenant overheard a man ask brittney to borrow her car. >> and within seconds she was shot multiple times. >> reporter: the shooter left without stealing her car or taking anything from her apartment. hillar moore is the district attorney for baton rouge. was there anybody else who overhead anything? >> no other witnesses. >> reporter: nothing. were there any fingerprints? >> nothing. >> reporter: any footprints? >> nothing. >> reporter: no eyewitnesses? >> nothing. >> reporter: so there's nothing there to tell you who might've done this? >> correct. >> reporter: almost immediately after the shooting, the story became more than just a local tragedy, when investigators here at the apartment noticed that right inside the front door on a living room table, next to her keys and her purse, was her cell phone. and it was an iphone. eight months earlier, in september 2014, apple had changed the iphone's operating system, adding a new layer of encryption that made it impossible, apple claimed, for law enforcement or the company itself to unlock anyone's iphone without knowing the owner's personal passcode. in addition, a new security feature would erase all the iphone's data if an incorrect passcode was tried ten times. with a warrant, baton rouge police obtained from brittney's cellular carrier a list of who she had called and texted, but they could not get the contents of those messages, or read anything she had stored on her phone, including a diary that brittney's mother says she kept on the phone. >> well let's say she was having trouble with somebody. it could lead us to that, some person, somebody. it could tell us exactly what the problems were about. >> reporter: almost a year later, the prosecutor has not charged anyone with the murder. do you think the answer to who did it is on your daughter's phone? >> oh, yes. >> reporter: you think it's there? >> i think what's in that phone can lead them straight to the person. >> when she died, the passcode died with her. >> reporter: cyrus vance is also a district attorney, not in louisiana, in new york, but he knows brittney's case well. >> it's one of many cases around this country that present similar facts. >> reporter: vance, who testified last month before a congressional hearing on encryption, has become a leading voice for local law enforcement officials. and it's local law enforcement, not national, which handles 95% of all criminal investigations in the u.s. >> prosecutors in houston have been locked out of more than 100 iphones last year, 46 in connecticut, 36 in chicago since january. >> reporter: his own crime lab in manhattan, one of the largest in the country, currently has 215 iphones he believes contain evidence, blocked by apple's encryption. vance says a 2012 case demonstrates how important iphone evidence can be. >> there was a homicide case we had not that long ago where a group of young men in northern manhattan were at a gathering in a room, and one individual was actually holding an iphone. when there was a noise, he turned to the door, entering the room, and in that door and captured on the iphone in a movie was a man with a gun who then shot the man who was holding the iphone-- killed him, and that phone dropped to the floor. >> reporter: that model iphone did not have the latest operating system and therefore was not encrypted. police caught the suspect, with the iphone video as evidence, convicted him of murder. >> if that had been an iphone 6 operating with an 8 system, the passcode would have died with that man, too. >> it's never been about just iphones. what we are talking about is the overall security of our entire digital ecosystem. >> reporter: kevin bankston is the director of the open technology institute at the new america foundation in washington. >> some have framed this as a debate between security and privacy but that is a false choice. >> reporter: he argued before congress that while encryption may end up shielding criminals, it protects everyone else from criminals who wish to steal information or do harm. >> it's always going to be a tragedy to see a particular awful crime. but we need to think rationally about what will make us all the safest. and what will make us all the safest and keep most of us safer from crime is strong encryption. >> reporter: joel reidenberg is the director of the center on law and information policy at fordham university law school. >> if there's a vulnerability in my smartphone-- then it means my contacts can be exploited by some malicious third party. many people store their passwords in their phone. my calendar, so someone knows where i'm going to be and when i'm going to be there. my movements, the g.p.s. log information, is in my phone. all of this could become available to malevolent-- third parties-- if there is a known vulnerability to the phone. >> reporter: apple's new encryption is part of "the snowden effect"-- the desire by many telecom companies and americans to protect their themselves from government intrusions following disclosures in 2013 by former national security agency contractor edward snowden about bulk electronic surveillance. 58% of americans said they are concerned about losing privacy in the government's efforts to fight terrorism in a cbs news- "new york times" poll last month. vance says local law enforcement plays by a different set of rules. >> we don't do bulk data collection. we operate phone by phone, device by device. we go get a warrant for every device that we are trying to open, and we don't make those decisions ourselves. judges make them. >> reporter: even without the ability to access encrypted iphones, reidenberg says law enforcement is living in a" golden age for surveillance." >> i can't drive down the street anonymously now. my picture's taken at every street corner. my license plate is captured. and the government can tail me wherever i go. they could do it before, but they had to spend a lot of money to have a cop car following every citizen. now it's ubiquitous, and it can be done on a mass scale. >> reporter: despite the locked iphone in the case of brittney mills, with apple's help, baton rouge police were able to retrieve 14,000 pages of brittney's emails and texts that she had backed up to the icloud, apple's wireless storage service. unfortunately, she stopped backing up her phone three months before her murder. apple rejected moore's request to unlock the iphone and declined to give the newshour a statement. so if she actually was killed by somebody she knew, you probably already have that person's name in your call list. >> it's possible that we have that name in the call list, but apparently, on this day, from what we can tell, there's no potential killer that calls her phone or makes a text to her, outside of family members, mother, sister, that leads us anywhere. so i'm left kind of with the unknown. >> so they're hoping there's evidence there. but they don't actually know that the evidence is on the phone. they're looking. they're fishing. they're fishing to try to find something. there's certainly a legitimate reason for the prosecutor to want to get access to that. the problem, though, is that what's decided in her case isn't limited to her case. it can affect people around the country in other kinds of cases where the circumstances will be far less compelling. >> reporter: district attorney moore wants information to help solve brittney mill's murder, but he admits he would like to use the tools to crack an iphone in any number of cases. yes, you want this information for a homicide. >> yes. >> reporter: what about for a burglary? >> yes. >> reporter: what about for shoplifting? domestic disputes? >> yes. >> reporter: where do you draw the line? >> i don't. you know, it's-- and i've heard- - >> reporter: i guess d.a.'s don't really draw that line? >> no, it's kind of, it's difficult to do so. so which victim is more valuable than another? you know, do you have a line? well sure, if i'm going to have a shoplifter versus a murderer, i'm gonna take whatever i can get. however, i mean, every case is important to somebody for some reason. >> reporter: moore supports a bill being drafted in the u.s. senate to give federal judges the power to order tech companies to grant law enforcement access to encrypted data. fordham law school professor joel reidenberg says everyone's privacy is at stake in how we treat alleged criminals. >> i think we also have to worry that if in pursuing them, we undermine the rights of the public at large. we begin to jeopardize some core values in our society. we presume everyone is innocent in the united states. right, do we really want to reverse that and presume everyone is guilty? >> yeah, we should have privacy. but to what degree? my goodness. and in our case we want this solved. >> reporter: but if you can't get into that phone, what are the odds you're going to solve brittney's murder? >> well, if that's the case, i'd like for someone to come in and say, "i killed brittney. i knocked on the door. here's my gun. the ballistics match." it's not going to happen. >> sreenivasan: this week, for the first time in the united states, doctors performed successful surgeries that transplanted organs from one h.i.v. positive donor into two h.i.v. positive patients. this has been hailed as a landmark development not only for h.i.v. patients who are at an increased risk of kidney and liver failure, but it is also expected to help reduce the waiting time for all potential organ recipients. for more, i am joined by dr. christine durand of johns hopkins university school of medicine, who was a part of the medical team that performed the surgeries. so how pig is this problem? put this in perspective for us. what are the consequences of an h.i.v.-positive person getting a transplant? >> these transplants are really an historic milestone. our group has been working for more than six years, and we had a congressional act passed, and this congressional act made it now legal to consider h.i.v.-positive donors for organ transplants. so this is a huge success, not only for our program, for patients with h.i.v. who are waiting for orgarngz but for everyone in the country who is waiting for an organ. we have more than 120,000 individuals on the wait list, and we don't have enough organs to go around. although this past year we performed more than 30,000 transplants, more than 20 patients die every single day waiting for an organ. so anyway that we can expand the organ supply, helps all of those people in need. >> sreenivasan: one of the questions people are going to have is how do organs do inside h.i.v.-positive patients? their immune systems are already suppressed. is there a risk the patient and organ won't last as long? >> so, certainly, there was a concern for many years that h.i.v.-positive individuals might not do as well with transplants. but we now have very large studies that have shown that h.i.v.-positive individuals do just as well as those without h.i.v. and it's now standard practice to use h.i.v.-negative donors for h.i.v.-positive patients on want wait list. >> sreenivasan: you know, this is maybe a unique question for a group of donors, but the types of drugs that they take and the cocktail that helps keep them alive, i mean, are there risks that come along where the recipient, their body has to kind of accept not just the organ but what's already gone into that organ? >> there are some extra considerations with these h.i.v.-positive-to-positive transplants. we know that the recipients are going to be exposed to the donor's virus. and so we have to take into account what tieches medication are needed to control that virus. we more than 20 h.i.v. medications, but there are some viruses that have drug reswrips. so we have to carefully compare the virus from the donor and the virus from the recipient to make sure that the recipient's h.i.v. medications are still going to be effective. >> sreenivasan: who is most likely to be on this list of h.i.v.-positive patients waiting for transplants? who does this affect the most? >> so it really affects a large number of individuals with pwen there are far fewer individuals dying from aids and infections. but at the same time, as people with h.i.v. live longer they're developing the same chronic diseases that the rest of the population develop. so up to a third of h.i.v.-positive individuals will develop chronic kidney disease, and many will also develop liver disease. the big deal about this is once you have these end-stage organ diseases with h.i.v. infection, you're actually at higher risk of dying. so that means h.i.v.-positive patients on the wait list are even in greater need of these organ transplants. >> sreenivasan: all right, dr. christine durand joining us from johns hopkins today. thanks so much. >> thank you. >> this is pbs newshour weekend, saturday. >> sreenivasan: archaeologists in egypt have completed the first phase of a new search of king tut's tomb. the question at hand is: might the tomb contain the undiscovered burial place of a famed egyptian queen? the newshour's ivette feliciano explains. >> reporter: in egypt's valley of the kings, near luxor, archeologists want to know what, if anything, lies behind the tomb's 3,000-year-old limestone walls. yesterday they completed 40 radar scans inside the tomb of tutankhamun, the boy king known as "king tut," who died at age 19 in 1323 b.c. scans last year suggested hidden chambers and passageways might exist, including a chamber that a british egyptologist, nicholas reeves, has proposed could contain the undiscovered tomb of queen nefertiti. >> i think there is still the possibility to find something that's really remarkable here. >> reporter: nefertiti, an iconic symbol of egyptian beauty, is widely believed to have been king tut's step- mother. her tomb would be one of the most significant archaeological finds in egypt since the discovery of tut's treasure- lined tomb in 1922. a joint egyptian-american team is now studying the scans. egypt's minister of antiquities said yesterday, no excavation will occur unless the scan's offer proof of a hidden chamber with something inside. >> we can make a drill, from the treasure small room on the side chamber, behind the reliefs, it will be only one inch diameter to reach this eventual cavity if it exists. >> reporter: it will take at least a week for preliminary results, and then more scans will be done from outside and above tut's tomb. egyptologist reeves remains hopeful queen nefertiti might be found. >> if i'm right, fantastic, if i'm wrong, i've been doing my job, i've been following the evidence trail, and seeing where it leads. >> reporter: egypt is inviting archaeologists and experts from around the world to examine the new data at a conference next month in cairo. >> sreenivasan: and timely, the hardest u.s. college to get into is california's stanford university. the prestigious silicon valley school accepted only 4.7% of the 44,000 prospective presk men who applied this year. harvard accepted 5.2%, making it the second most selective private university survey by the "washington post." the post finds the odds of getting into an elite school are better if you apply for early decision in the fall. that's all for this edition of pbs newshour weekend. i'm hari sreenivasan. thanks for watching. have a good night. captioning sponsored by wnet captioned by media access group at wgbh access.wgbh.org >> pbs newshour weekend is made possible by: lewis b. and louise hirschfeld cullman. bernard and irene schwartz. judy and josh weston. the cheryl and philip milstein family. the citi foundation. supporting innovation and enabling urban progress. the john and helen glessner family trust. supporting trustworthy journalism that informs and inspires. sue and edgar wachenheim, iii. corporate funding is provided by mutual of america-- designing customized individual and group retirement products. that's why we are your retirement company. additional support has been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. ank you. female announcer: rebels with a cause is brought to you by: [soft instrumental music] ♪ [people chatting excitedly]