Produced By Patti Aronofsky, Katherine Davis, Elena DiFiore and Mead Stone
[This story previously aired on March 28, 2009. It was updated on Aug. 17, 2013]
During the early morning hours of Nov. 15, 2004, Peter and Joan Porco were brutally attacked by an ax-wielding intruder in their bedroom. Peter Porco was murdered, his wife left for dead.
Miraculously, she was clinging on to life when investigators and medics arrived at the crime scene hours later. Suffering from severe injuries, police say Joan Porco indicated to them who the killer was with a nod.
But as "48 Hours" correspondent Peter Van Sant reports, she says she has no memory of that. And she says she never would have implicated the person who faced trial for the murder of her husband.
Detective Chris Bowdish couldn't believe what he was seeing. Minutes after discovering the body of Peter Porco, he was certain he was about to learn the identity of the killer from Peter's dying wife, Joan.
"And I said to her, 'Can you hear me?' And she nodded her head 'yes.' I then started feeling that this woman knows what's going on," he said.
Although Bowdish had only been in the house for minutes, he also felt he knew what was going on. "I could see there was no break in. There was no forced entry," he explained.
Instead of a broken lock, there was a house key in the front door. It was a spare key that was usually hidden in a flower pot by the front entrance.
"The house wasn't what we call 'tossed.' The drawers weren't pulled out, they weren't dumped," Bowdish said. In the dining room was Joan's purse and its contents, all undisturbed. Bowdish says he felt it was an inside job.
But who would want to harm the Porcos? Married 30 years, the couple lived in Bethlehem, N.Y., a bedroom community just outside of Albany. They had two sons, 23-year-old Jonathan, in the Navy in South Carolina, and 21-year-old Chris, a student at the University of Rochester.
In a strange coincidence, Det. Bowdish had met the Porcos two years earlier, when they reported the theft of laptops during a burglary. He also learned they had two sons. At the crime scene, he was wondering about the whereabouts of Jonathan and Christopher.
As the paramedics struggled to get Joan oxygen, Bowdish approached her.
"I said, 'Did a family member do this to you?' And she nodded her head up and down clearly, 'yes'. Now everybody in the room's standing there at this point, I've got witnesses."
First responders Kevin Robert, Jim Regan, and Dennis Wood couldn't believe it. "I've never seen anybody with this massive of facial and head trauma and still be alive and actually able to communicate like she was," said Wood.
Joan had been following directions like "straighten your arm" and "stop moving your legs." But this was different. Before their eyes, Joan was about to identify the killer. The paramedics watched as she nodded her head in response to the detective's questions.
"And I said to her, 'Did Jonathan do this to you?' And she clearly shook her back and forth, 'no.' At this point I knew she could hear me. I knew she understood the answers to the questions," Bowdish recalled.
"And I said to her, 'Did Christopher do this to you?' And she then shook her head up and down. She nodded. 'Yes he did.'"
Within minutes, Joan was rushed to the hospital and police began looking for Christopher.
More than 200 miles away, Christopher Porco says he didn't know police wanted to talk to him. He says he was in his dorm room when he got a phone call from a local reporter.
"She asked me if I had any comment on my parents being killed that day. I kind of dropped the phone and was completely shocked, and you know disbelief," he recalled. "I called the Bethlehem Police Department."
When he called police, Christopher asked whether the operator had any information about his parents; the operator asked about his whereabouts.
"The woman on the phone said she couldn't tell me anything but they would call me back. So I sat in my room and waited," said Christopher.
Within the hour, police confirmed his father was dead. Christopher's brother Jonathan learned the devastating news at his Navy base, as an uncle rushed Christopher to his mother's bedside at the hospital.
"I saw her - she was swollen and covered in tubes. And my reaction was I burst into tears. I fell on the floor right there," said Christopher.
As Joan underwent emergency surgery, Christopher agreed to go to the police station where he was questioned for six hours. "I wanted to be as helpful as I could. I knew that in cases like this, you know, the quicker the better. So I wanted to give them what they needed to figure out who did it," he explained.
Asked if he carried out the deadly attack, Christopher replied, "You know, I can't say enough, absolutely no. I would never do anything like that to anyone let alone my parents who I love dearly."
Bowdish's number one priority was finding out where Christopher was at the time of the attack.
Some 16 hours after Joan identified her son as her attacker, detectives were knocking on doors at Christopher's dorm. It quickly became clear that none of his frat brothers could back up Christopher's alibi that he was asleep on the couch in the dorm lounge.
"It just so happened that some guys were up and we stayed up until like 3:30 a.m. It's a square room and some couches and TV - it's not like maybe he was there and we overlooked him. He wasn't there," said one of the fraternity brothers.
Detectives searched his room, taking clothes and a computer; they even impounded his car, a bright yellow Jeep Wrangler.
Back at Albany Medical Center, Joan remained unconscious, clinging to life and undergoing many hours of surgery.
Former youth minister Joe Catalano rushed to Joan's bedside to comfort Christopher. He was struck by Christopher's odd behavior. Asked if he sensed any bit of grief with Chris, Catalano said, "None whatsoever."
By now, Christopher was the prime suspect in the murder. But police had to figure out how he could have done it.
Christopher was at the university the morning his parents were discovered, more than 200 miles from the crime scene. And while his fraternity brothers hadn't seen him the night before, another student did see him out jogging the next morning.
The case appeared to have hit a wall - until investigators decided to check several campus security cameras. What they saw changed everything.