UTICA, N.Y. -- Bradley Napierkowski's murder trial is underway after being put on hold for more than a year while he sought treatment for a brain tumor. He's charged with second-degree murder and attempted robbery in the July 2005 death of Junior Mercurius. On Tuesday, witnesses for the prosecution took the stand.

Marques Williams, who's in jail on an unrelated gun possession charge, took the stand with the understanding he would not be prosecuted in exchange. During testimony, he said Napierkowski didn't kill Mercurius, but another man by the name of Mark Bell did, which contradicts statements to police.

"So why are you bringing it up now," asked Oneida County Assistant District Attorney Paul Hernon.
"Because I don't feel it's right to lie on somebody else," said Williams.

"Marques, you lied on Bradley. If what you say is true, you lied on Bradley back in 2006," said Hernon.
"Yes," said Williams.
"Why," Hernon asked.
"Because somebody threatened my mother," Williams said.
"And you never told the police that," asked Hernon.
"No," Williams replied.
"You never told the police about Mark Bell," said Hernon
"No," said Williams.

Judge Barry Donalty called for a short recess so Williams' attorney could be present. Williams returned to the stand with his attorney and again changed his testimony, taking back the accusation against Mark Bell.

"Did anyone really ever threaten your mother," Hernon asked.
"No," Williams said.
"So everything that you told us about Mark Bell is inaccurate and basically untrue," asked Hernon.
"Yes," Williams responded.

Witness testimony will continue Wednesday in Oneida County Court. This is a bench trial, which means there's no jury and the judge will decide.