One lawmaker who voted against the repeal of the death penalty Wednesday, came to the debate with a unique perspective — he was a defense attorney for a man exonerated of murder.

When Rep. David Labriola, R-Oxford, isn’t at the state Capitol, he works as a private criminal defense attorney. That’s how he came to know Miguel Roman. In the 1980s, Roman was convicted of killing a pregnant Hartford teenager and sentenced to life in prison.

Labriola said the conviction was based mainly on testimony from a man who shared a cell with Roman and claimed to have overheard him confessing to the murder. Even back then, Labriola says he didn’t believe his client was guilty. He told the court as much during Roman’s trial.

But Roman sat in prison for 20 years until the Connecticut Innocence Project helped link DNA evidence found at the crime scene to another man suspected of other murders. In 2008, he was released.

Labriola said Roman’s exoneration was a “surreal” experience.

“I was delighted,” he said. “It’s amazing what happens when you live long enough.”

He said the sophistication and reliability of modern DNA analysis is one of the reasons he supported the death penalty statute, which a majority of his colleagues voted to take off the books Wednesday. DNA evidence provides the state with greater assurance that offenders handed guilty verdicts are, in fact, guilty, he said.

Labriola recalled that he did present DNA evidence in Roman’s case more than 20 years ago. He said it was one of the first DNA cases in the country. Though the DNA clearly didn’t belong to Roman, prosecutor John Massameno was able to argue that presence of another person’s DNA did not mean Roman was not guilty.

While the possibility the state may someday execute an innocent person is often used as an argument to repeal the death penalty, Labriola said he’s confident that would not have happened. It’s tougher to get a death penalty conviction in Connecticut than any other state with a capital punishment statute, he said. He also vouched for the competence of the lawyers who defend death penalty cases.

“Our Capital Defense Unit is impeccable,” he said.

Labriola said it’s clear none of the people currently on death row are innocent. If anything, he said his time as a lawyer has only strengthened his support of the death penalty.

“I think working as a defense attorney for the last 25 years gives me insight into a wide range of issues and some crimes are so heinous that the death penalty is the only justifiable punishment,” he said.

However, Karen Goodrow, director of the Innocence Project that helped free Roman, disagreed that an innocent person would never be executed in Connecticut. That’s what she told the Judiciary Committee during a public hearing on the bill in March.

“I’m here to tell you from my experience, it just a matter of time before we have somebody on our death row who is innocent and I say that because contrary to what we see on television, most cases do not contain DNA,” she said.

Goodrow said DNA evidence is only available in about 10 percent of the cases her organization investigates. In some cases, like Roman’s, people are convicted even when there is DNA evidence, she told lawmakers.

“Miguel, it’s worth pointing out in that case, horrible case, a pregnant 17-year-old girl was raped, bound, murdered, there was DNA back at the time of Miguel’s trial that excluded him from the vaginal walls of the victim. It excluded him, but the state’s attorneys — of course, not [Chief State’s Attorney Kevin] Kane — prosecuted the case for murder on the theory that, well somebody else must have had sexual contact with her,” she said.

The House gave final passage to a bill that prospectively repeals the death penalty on Wednesday. Gov. Dannel P. Malloy said he would sign the bill once it gets to his desk.