Las Vegas police Capt. Chris Jones said Monday that investigators were tracing places where Ammar Harris lived and worked in the past.
Public records show Harris lived in South Carolina and Georgia; was convicted in Atlanta in 2005 of marijuana possession; and was arrested in Miami in December on a reckless driving charge.
Harris also was arrested last year in Las Vegas on pandering, kidnapping, sex assault and coercion charges.
Harris is accused and firing shots into a Maserati, killing an aspiring rapper, and causing a crash and explosion that killed two people in a taxi at the heart of the Strip.