OKLAHOMA CITY - The Oklahoma County District Attorney filed a first-degree murder charge Tuesday in a 34-year-old case.

Raul Sierra is accused of killing 23-year-old Wilfredo Roberto Matos Osorio in an Oklahoma City home. Authorities said Osorio’s body was found in an embankment of a bridge in Pottawatomie County on November 28, 1982. Investigators said he died of multiple gunshot wounds.

An affidavit outlines the information investigators collected for several years after the body was discovered. But the Oklahoma State Bureau of Investigation (OSBI) said the forensic testing at the time didn't provide many leads.

Court documents showed, this year, a special agent with OSBI learned three people close to the case had died. The agent re-interviewed several witnesses, the document said. One reportedly said he saw another man shoot Osorio with a .22 caliber pistol. And then he remembered standing in the kitchen at the home where it happened, looking through a cutout toward Sierra and the victim. He told investigators he saw Sierra pull the trigger on a 20-gauge shotgun, the affidavit said.

An OSBI Criminalist said the evidence found at the scene and in the victim's body is consistent with the firearms.

Biological evidence was also recently tested at OSBI's lab and the test results showed the probability of the blood and human tissue found at the crime scene matching someone other than the victim is 1 in 2.17 billion, according to the court filing.

The OSBI said the second person implicated in the murder is dead and Sierra was arrested in New Orleans last week. Sierra will eventually come to Oklahoma to answer to the murder charge, OSBI added.