Dodging an onslaught of gunfire Thursday, Chattanooga police officers killed the shooter who gunned down four U.S. Marines and one sailor and the city's police chief believes their actions saved the lives of others, authorities said Friday.

"There is absolutely no doubt in my mind that Chattanooga police officers saved lives yesterday," Chattanooga Police Chief Fred Fletcher told the Tennessean  Friday during a mid-afternoon news conference in Chattanooga in connection to the mass killing at a military reserve center on Thursday.

Fletcher said his officers — in an act he described as heroic — engaged the gunman "immediately, aggressively" with the sole intent that he harm as few people as possible.

Recounting the events, Fletcher said police officers initially engaged the shooter at the reserve, but he was a moving target and able to kill the four Marines. The military identified the victims as Staff Sgt. David A. Wyatt of Burke, N.C.; Gunnery Sgt. Thomas Sullivan of Hampden, Mass.; Lance Cpl. Squire K Wells of Cobb, Ga., and Sgt. Carson Holmquist of Polk, Wis.

Immediately after the initial reports of gunfire, which broke out just after 10:45 a.m., officers began searching and located the gunman driving down the highway.

Fletcher said officers engaged with the shooter, who authorities identified as 24-year-old Muhammad Youssef Abdulazeez of Hixson, Tenn. When the suspected shooter hit an officer with a bullet, Chattanooga policemen dragged the wounded officer away and returned fire.