wait till because again. but the trail grew cold. the file forgotten, until decades later, someone dusted it off. see the thing that s hiding in plain sight. there were clues. a mysterious weapon made of wire, the wedding invitation, a midnight sale to know where. where they enough to catch a killer? i was 100 percent confident now, the showdown a determined prosecutor against a famed defense lawyer, who helped set ogs in free. i m on the right side. after 35 years, it was finally time for justice. it s been a long journey. in this makeshift workshop, had to be for what he intended. carefully, got the lengths of a two of them. just a few inches each, sand them down, joe the whole in each one. he found a piece of wire, he doubled it for strength. his perfect weapon for his perfect crime. outside, in the sunshine, it was the summer of 1979. aides hadn t happened to us to, north of the internet, nor did cell phones, norway to re-dna. all of those
a loud squeal. reporter: after he heard that, said a neighbor, he caught a glimpse of the man who may have been the killer. a slender young man with dark, curly hair. not much to go on. he looked at the back of the suspect as he ran down the driveway, into the street. carrying something? a small satchel. reporter: there couldn t have been much inside that black bag, because very little was taken from lynn s apartment. only her wallet, keys and one particular piece of jewelry. she had a necklace on, a pendant. at the scene we found a broken clasp. but no chain? no chain. reporter: but the killer left something of his own behind, something detectives didn t notice. until the coroner moved ellen s body. it appeared to be a homemade
set of wounds that the detectives couldn t figure out, deep cuts on her neck, which may have explained a horrifying sound. reporter: how would you describe that screaming? a squeal. allowed squeal. reporter: after he heard that, said a neighbor, he caught a glimpse of the man who may have been the killer. a slender young man with dark, curly hair. not much to go by. he looked at the back of the suspect as he ran down the driveway, into the street. carrying something? a small satchel. reporter: there couldn t have been much inside that black bag, because it was taken from lynn s apartment. only her wallet, keys and one particular piece of jewelry. she had a necklace on, a pendant. at the scene we found a broken clasp. but no chain? no chain.
and now the camera is turning into a retail worker s secret weapon. when this interactive technology is triggered, a human set of eyes, ears and voice is added behind the lens. speaking specifically to the white male hanging out in front of the store. it is time for you to leave! you ve been asked to leave. you will not receive any further warnings. the police will be dispatched. you will be arrested and cited for trespassing. leave now! at west tech interactive securities, elena evans is responding to a problem a store is having with loiterers. she s using special two-way surveillance equipment to monitor and respond to this situation as it s happening. are they still outside? i can t see them. okay. you can t see them at all anymore? do you think they went away? okay. no problem. if you have further trouble you just let us know, okay? thank you. bye-bye. the system is activated when a clerk pushes buttons placed strategically inside a business or squeezes a pendant. what th
or squeezes a pendant. what this does is it sends a signal to our system in the store which sends it through a phone line to west tech. 30 to 40 seconds later west tech is online looking in. you re being monitored and recorded. how is everything tonight? we re doing great, thank you. and when a theft does occur, employees are instructed to let it happen. don t intervene or resist and when the bandit leaves, hit the alarm. the clerk hit their alarm button stating that this individual took two 18-packs of, i believe, it was bud light and basically ran out with the beer. in an instant, the intervention specialist is able to retrieve video of the theft from the store s surveillance system. that s the proof right there that he didn t pay and you can see him run right by the counter. still ahead