(STMW) — Police claim a man exonerated of a murder charge in 2012 after serving 17 years in prison was fatally shot by someone he was trying to rob Tuesday afternoon on the Near West Side.

Alprentiss Nash, 40, was shot in the chest in the 400 block of South Paulina at 2:20 p.m., according to police and the Cook County medical examiner’s office.

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Nash tried to rob 30-year-old Mount Prospect resident Paul Vukadinovic, “with whom he had a long drug history,” according to a police statement released Thursday.

Both men were armed and they exchanged gunfire. Nash, of the 100 block of North LaPorte Avenue, was taken to Stroger Hospital, where he was pronounced dead, authorities said.

The shooting is “being explored as a possible self-defense case,” police said.

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Vukadinovic was charged with aggravated unlawful use of a weapon and carrying a loaded gun without a concealed carry permit. He is due in court Friday.

Katherine Zellner, an attorney who represented Nash in a wrongful conviction lawsuit, said in a statement: “Our client, Alprentiss Nash was murdered in Chicago yesterday during a failed robbery attempt.”

Nash was convicted of the murder and robbery of a Chicago man on the South Side in 1995, the Sun-Times previously reported. He was incarcerated from April 30, 1995, to Aug. 30, 2012, after Cook County State’s Attorney Anita Alvarez vacated his conviction when new DNA evidence exonerated him.

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 (Source: Sun-Times Media Wire © Chicago Sun-Times 2015. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)