BIRMINGHAM, Ala. (AP) — Police in Alabama say a 41-year-old man was found shot dead on a street curb.

Al.com reports emergency responders in Birmingham pronounced Jeffery Tubbs dead on the scene Wednesday night when they found him shot and lying on his back.

Birmingham police say Tubbs was the third slaying victim discovered in the city in less than eight hours. Police Sgt. Bryan Shelton said Thursday there is no known motive and investigators aren't sure what led to the shooting. He said police were familiar with Tubbs from a confrontation a few days earlier, but he declined to give details.