but i can honestly say it was definitely back and forth, you know what i mean? mm-hmm. reporter: their troubles were well-documented. in 2008, ann had cara arrested for assault. she dropped the charges. but a year later, each woman filed for divorce, with ann asking for custody of daughter brianna. within weeks, each applied for a restraining order against the other. brianna was caught in the middle. when the other would try to pull brianna away that was problematic. reporter: so the child was the glue that held them together, but it was mm-hmm. reporter: also the source of a lot of this friction, huh? correct. reporter: money was an issue, as it so often was with ann. cara was frugal. ann, free-spending.
persons of interest or suspects, call them what you will. reporter: but carla told investigators she went to her gym, a 30-minute drive from the rintala home, about 3:00 p.m. the afternoon of the murder. said she went out for a long run. then left the gym at 7:00 p.m. investigators located security images that supported her account. is carla s alibi rock solid? or does it have a window for foul play? i would say it s pretty rock solid unless she had access to a helicopter. reporter: that left investigators with one remaining suspect, the one who d topped their list since the night of the murder. the person who knew ann best, who loved her, and who fought with her cara. because as sunny as these two seemed in public, sometimes behind closed doors they went after one another. as cara admitted in her police interview. we d argue and it would get physical, absolutely. and i m no angel.
take it down take it down reporter: cara rintala s family and friends agree on a couple of things. first, that cara is a great mom. do i do i reporter: and if she has to sing herself silly to entertain her daughter well, she s in. my beautiful daughter brianna reporter: the second thing friends say is this, cara did not murder her wife. not in a million years. suzanne cordes, who first met cara at church, says she knows her like a sister. cara would never do that. the woman that i know, the devoted, loyal, compassionate, caring, thoughtful, faithful mother that i know would never ever do that to her wife. reporter: when the third trial commenced, friends and family sat behind cara in court, practically willing a victory. attorney david hoose opened, as
in its own expert to knock down the prosecutors argument that one of the rags contained ann s dna. i have no idea what the source of the dna on that rag is. reporter: but perhaps the most damaging evidence against cara was the paint. attorney hoose went after the prosecution s paint guy on cross. his weapon of choice? sarcasm. you re the first guy as far as you know who has ever testified about reading wrinkles and cracks in paints, is that correct? that i m aware of. your honor, can we please change the tone here? reporter: the defense attorney had to persuade jurors that cara hadn t poured the paint. he accused the paint expert of buying into the first responders observation that the paint was wet. first responders these are people you ve never met, correct? you don t know how much training they have or if they ve even seen a bucket of paint before, correct? yet you re ready to credit their subjective impression that the paint was either wet or shiny, correct?
for murder? well maybe this ann, the drama queen, had angered him when she left her wife for her old girlfriend. he described that he had a big fallout with ann. is that correct? yes. and the fallout was when he became aware that ann was seeing an old girlfriend. correct? yes. an old girlfriend named carla daniele. correct? correct. reporter: a wisp of doubt, cara s separation. and what about carla? remember, she said she d been miles away at the gym and out running on the day of the murder. security images seemed that support that account, but the defense produced a bank record dated the day of ann s death from an atm closer to the crime scene than the gym. did you ever ask her about how that could have happened if she was running in east longmeadow? i don t know that i ve never asked her that. reporter: the name of the game for criminal defense lawyers is creating reasonable doubt. had the defense finally gotten there with all 12?