A $100,000 reward has been offered by law enforcement for information leading to the arrest of the 31-year-old conservative activist's killer. The FBI issued grainy photos of a person of interest – not yet a suspect – and asked for the public's help identifying him.

Asked about the identity of the shooter, Utah Gov. Cox said a person of interest was in custody. Utah's Commissioner of Public Safety said \

Authorities arrested a man shortly after the shooting but later said he didn't match the suspect's description. They're now interviewing a \