Did Richard Lapointe murder Bernice Martin? That question hung over the proceedings in his habeas hearing earlier this month in Rockville.

Lapointe, who suffers from Dandy-Walker Syndrome, a serious brain malformation, and various disabilities, was convicted in 1992 of sexually assaulting and murdering his wife’s 88-year-old grandmother in her apartment in the Mayfair Gardens complex in Manchester on the evening of March. 8, 1987. He was sentenced to life without parole.

The hearing is not about his guilt or innocence. It’s about his claim that his lawyer in an earlier habeas hearing provided ineffective assistance by failing to raise several issues, including the suppression of evidence pertaining to the likely time of the crime that supported his alibi.

But the question was there — and remains: Did Lapointe murder Martin?

At first glance, the answer seems obvious. During a nine-hour interrogation on July 4, 1989, he signed three statements confessing to the crime. There was a semen stain on Martin’s bedspread that revealed the perpetrator had Type A blood and was a secretor, meaning the antigen in his blood is secreted into other body fluids. Further, the semen contained no sperm. Lapointe has Type A blood, is a secretor and had a vasectomy.

Lapointe’s statements, however, contain a number of inaccuracies — for example, about what Martin was wearing, how she was assaulted and how she was murdered. There is reason to think he confessed because the interrogators persuaded him that he committed the crime; in one, he said, “If the evidence shows I was there, and that I killed her, then I killed her, but I don’t remember being there.”

The Manchester police had recording equipment but the interrogation wasn’t recorded.

The fact that Lapointe has Type A blood, is a secretor and had a vasectomy appears damning. But he’s certainly not the only person with those attributes: 40 percent of the population has Type A blood and 80 to 85 percent are secretors. A study in the 1990s found 38 perent of men over 40 had vasectomies. At the time of the murder, possibly 10 percent of all men over 40 had Type A blood, were secretors and had a vasectomy.

Both habeas hearings have turned up tantalizing evidence that someone other than Lapointe murdered Bernice Martin. A pair of men’s gloves, too large for Lapointe, was found in the bedroom, one glove on the floor, the other on the bed. They had strands of Martin’s hair on them. A forensic scientist testified the left glove contained a mixture of three DNA profiles, none of which matched Lapointe’s.

Martin wore a blue sweater that day. It was found on the bedroom floor. There was a pubic hair on it that came from someone other than Martin or Lapointe. There were head hairs on the bed that came from someone other than Martin or Lapointe.

A woman reported that as she drove by Mayfair Gardens at about 8 p.m. that evening, a man came running out of the driveway and into the street. He was running “like he was being chased by a pack of dogs.” She had to swerve to avoid hitting him. He continued running through the nearby intersection and disappeared behind a building on the other side of the street. He was white, 35 to 40, 5 feet 10 or 11, medium build, with straight black disheveled hair.

Three days after the murder, Frederick Merrill, a man with a criminal record, was arrested for sexually assaulting a middle-aged woman in her home in South Windsor a few miles away. There were some unusual similarities in the two crimes, including the way the victims were tied up and assaulted. Merrill reportedly resembled the man seen running out of the complex and had been seen that weekend in Kelly’s Pub, just up the street from Mayfair Gardens. He’s now serving a 20-year sentence for sexual assault.

The habeas hearing will resume and conclude in July. Perhaps, if Superior Court Judge John J. Nazzaro vacates Lapointe’s conviction and orders a new trial, we may be closer to knowing who murdered Bernice Martin.

•David R. Cameron is a professor of political science at Yale University.