Randall Dale Adams, who spent 12 years in prison before his conviction in the murder of a Dallas police officer was thrown out largely on the basis of evidence uncovered by a filmmaker, died in obscurity in October in Washington Court House, Ohio. He was 61.

Mr. Adams had chosen to live a quiet life divorced from his past, and when he died on Oct. 30, 2010, of a brain tumor, the death was reported only locally, said his lawyer, Randy Schaffer. The death was first widely reported on Friday.

The film that proved so crucial to Mr. Adams was “The Thin Blue Line,” directed by Errol Morris and released in 1988. It told a harrowing story, and it had the effect of helping to bring about Mr. Adams’s release the following year.

“We’re not talking about a cop killer who’s getting out on a technicality,” Mr. Morris said when Mr. Adams was set free. “We’re talking about an unbelievable nightmare.”