CNN is running a video taken by a bystander Ismael Dejesus showing a shooter with a rifle on the street. Dejesus described the rifle as a "AR-15 with large mag". Later added the shooter had multiple 30 round mags.
The shooter drive up in a black SUV and got and started shooting. He was engaged by an officer in a shootout. The shooter walked over to the downed cop and shot him multiple times on the ground. "Execution style"
Dejesus shot the video from his hotel room (looks like 3-5 stories above street level).
Dejesus added man was in camo but he could not determine the man's race from his location.
CNN had a retired ATF officer comment. Said many weapons look like AR-15. Regardless of exact type he noted a cop with a 9 mm is badly outgunned in such a situation.
A later video by a Michael Kevin from a different angle and at street level, shows multiple cops engaged in a subsequent fire fight. The officer shot earlier can be seen on the ground in the background.