( CNN ) -- The Tennessee man accused of selling the gun used to kill former NFL quarterback Steve McNair is in custody facing a federal charge of being a convicted felon in possession of a firearm , authorities said Friday . Police say Adrian Gilliam admitted he sold Sahel Kazemi the gun she used to kill NFL quarterback Steve McNair . `` This is another example of what can happen with a gun when a felon is selling it on the street with little to no interest other than just selling it for 100 bucks , '' said Nashville , Tennessee , Police Chief Ronal Serpas . Authorities said federal agents traced the gun used in the Fourth of July murder-suicide to Household Pawn in Nashville , which sold it in January 2002 . `` Further investigation revealed the 9 mm pistol was later sold for approximately $ 100 to Adrian Gilliam approximately one to one and a half years ago , '' Nashville police said in a news release . Gilliam , 33 , of LaVergne , Tennessee , told detectives that on July 2 he sold the gun for about the same price to Sahel Kazemi outside a shopping mall . Police said Kazemi , McNair 's 20-year-old girlfriend , used the gun two days later to fatally shoot McNair -- a former Tennessee Titans quarterback and married father of four -- and herself in McNair 's condominium in downtown Nashville . Gilliam had been convicted of second-degree murder and attempted armed robbery in Florida in 1993 , according to the new release , and those felony convictions meant that he could not legally be in possession of a firearm . Along with Serpas , the announcement of the arrest was made by Edward M. Yarbrough , the U.S. attorney for the Middle District of Tennessee ; James M. Cavanaugh , the Special Agent in Charge of the Bureau of Alcohol , Tobacco , Firearms & Explosives ' Nashville Division ; and Mark Gwyn , director of the Tennessee Bureau of Investigation . CNN 's Shelby Lin Erdman contributed to this report .
Police say Adrian Sahel Kazemi told them he sold gun to Sahel Kazemi 's girlfriend on July 2 . On July 4 , McNair shot the quarterback to death , then killed herself . Gilliam had felony convictions in Florida from July 4 , police say .