(CNN) – Deon Patrick was 20 when his life was stolen from him. In 1992, he was one of eight men arrested in the deaths of a drug dealer and a prostitute on the north side of Chicago.

Patrick immediately said he was innocent. No physical evidence linked him to the murders. But 30 hours in police custody without a lawyer present can have a way of changing a young man's mind.

At one point his friend, co-defendant Daniel Taylor, was brought into the interview room. He told Patrick to just tell the police “what they wanted to hear, and they could go home.”

So he broke down, signed a confession, and was later sentenced to life in prison without parole.

Twenty-one years ticked by.

“There are days when you actually start to give up,” Patrick told CNN.

Patrick was exonerated last month. And he is not alone.

According to a new study by the National Registry of Exonerations, there were a record number of wrongful convictions overturned last year in the United States. Nearly half of them were based on murder trials.

“The psychological techniques that are actually taught at the police academy lead to many false confessions,” Rob Warden, executive director at the Center on Wrongful Convictions.

“After hours and hours of interrogation, people lose their resistance,” said Ward.

Interrogations that last “20, 30 hours with minimal sleep, and minimal food, and minimal ability to use the bathroom – at some point you’ll say absolutely anything to stop it,” he said.

Patrick said he would like to see “a sense of accountability” someday for people “who do this and cut corners to get cases closed.”

The father of two is looking forward to the years ahead as a free man. He plans to go back to school, and find a job.

“I just want to enjoy the rest of my life, and enjoy the rest of my life with my kids and grandkids,” said Patrick.

Patrick says he and his co-defendant, Daniel Taylor, would not be free today, if it were not for the work of the Center on Wrongful Convictions and the media attention they received.

He advises others who are innocent prisoners to reach out, and write to organizations to get help.

“If you don’t get that, sometimes you will find yourself stuck, even though you know you didn't do it, but the courts will continue to shoot you down,” said Patrick.

And he had one more message for other innocent men and women serving time.

“Keep the hope alive. And just know that one day the truth is going to finally come out.”

Watch CNN's "Piers Morgan Live" for an interview with Anthony Yarbough and Sharif Wilson, two men also recently released from prison after serving 21 years.