A Chicago man who served 17 years in prison for murder before being cleared of the crime has been shot and killed almost three years after being released, police said on Wednesday.

Alprentiss Nash, 40, was fatally shot on Tuesday after an argument during “some sort of transaction” between Nash and his attacker, Chicago police spokesman Anthony Guglielmi said. He said police were questioning a person of interest.

Nash was convicted in the 1995 murder of Leon Stroud on Chicago’s South Side, based on witness testimony, though he always professed his innocence. In 1997 he was sentenced to 80 years in prison.

He was released in August 2012 after DNA tests on a ski mask recovered from the scene matched the genetic profile of another man.

Nash later received a certificate of innocence and a settlement of more than $200,000 from the state. A federal civil rights case pending against the city of Chicago and the police department will continue with Nash’s 22-year-old son serving as the person who brought the suit, said attorney Kathleen Zellner, who helped free Nash.

Nash recently had talked about moving south, perhaps to Florida or Louisiana, because he no longer felt safe in Chicago, said Zellner and Nash’s mother, Yvette Martin.

“He really just wanted to disappear and get out of here” because he was afraid he was being targeted for money, Zellner said.

Martin said her son had gone to culinary arts school and dreamed of opening a restaurant, but struggled to hold down a job because of his imprisonment. She said he also spoke of moving to Louisiana and buying cattle with some cousins once his civil case was settled.

“He jumped all those hurdles and then this happened,” she said.