On the evening of March 8, 1987, Bernice Martin was raped and murdered in her apartment in Manchester, Conn.

More than five years later, her granddaughter’s husband, Richard Lapointe, was convicted of the crime and sentenced to life imprisonment without possibility of release. Now, the courts are questioning the confessions that have kept Lapointe behind bars for the past two decades.

The Connecticut State Appellate Court announced its decision to retry the case on Monday, more than 20 years after Lapointe, who is mentally impaired, was initially arrested in 1989. The court decision cited the prosecution’s failure to present a crucial piece of evidence as grounds for his retrial. As a result, the new trial will determine the validity of Lapointe’s initial conviction. Lapointe’s attorney, Paul Casteleiro, said he is optimistic Lapointe will be found innocent.

On the night of July 4, 1989, police investigators asked Lapointe to come to the station for questioning. He complied, believing he would be home in time to watch the fireworks with his wife and young son, said Robert Perske, an expert on mentally impaired people moving through the justice system who has worked with the Lapointe case for 20 years. But investigators held Lapointe for nine-and-a-half hours, during which he confessed on three separate occasions to a crime he said he did not remember committing.

On the wall, Perske said, police had posted a chart listing types of evidence, including “fingerprints,” “DNA” and “pubic hair,” each with a large red checkmark. Throughout the night, police repeatedly referenced this chart, which was fake, hoping it would spur Lapointe to confess, Perske said.

But Lapointe suffers from Dandy Walker Syndrome, Perske said, a mental disability that causes the brain to fill with fluid. In Lapointe’s case, this has prevented him from learning to read or write.

Psychology professor Kristi Lockhart said that 25 percent of all wrongful convictions involve false confessions, adding that young and mentally impaired suspects are particularly prone to giving false confessions in circumstances similar to those surrounding Lapointe’s interrogation.

According to Perske, Lapointe told investigators “if you said I killed her then I did, but I don’t remember being there” at one point in the night. Perske, along with a team of 25 supporters, known simply as the Friends of Richard Lapointe, said his case is a breakthrough for all mentally disabled suspects who have been wrongfully imprisoned.

“We really hope that future prosecutors, judges [and] defense attorneys … get more informed about the human beings that are involved in this game, so that they can not just look at how you can trick somebody into solving or getting these cases solved, but actually looking at whether justice has been done,” said George Ducharme, a member of the Friends.

Over the past 20 years, the Friends of Richard Lapointe have been visiting the prison and working to overturn the conviction that they say was wrongfully issued. After Lapointe was sentenced, he lost contact with his family, and the Friends became his only visitors. They describe Lapointe as a jokester who prides himself on his puns but said he has grown more pessimistic in recent years.

“He told me that he was starting to lose hope and began to believe he would leave prison in a body bag, instead of leaving as a free man,” Anne Treimanis, webmaster of the Friends website, wrote in a Thursday email. “Waiting 20 years to be exonerated for a crime he did not commit is a very long time to wait.”

Lapointe’s attorney said that the state of Connecticut can either send the case to the state Supreme Court, which would decide if it wishes to review the case, or can do nothing, in which case a fresh trial will be held. Mark Dupuis, a spokesman for the chief state’s attorney’s office, said that his office is still reviewing the court’s decision and has not yet determined what its next action will be. But Casteleiro said recent events suggest the state is likely to do nothing, sending the case back to the original trial court, and he is optimistic that Lapointe will be found innocent.

More than 2,000 people have been wrongfully convicted of crimes in the United States during the past 23 years, according to the University of Michigan Law School and Northwestern University’s Center on Wrongful Convictions.