Suge Knight is one step closer to getting justice -- cops now believe they know who shot him 6 times on the Sunset strip ... but they still face a major hurdle to closing the case.

Law enforcement sources tell us they've reviewed security cameras and spoken to multiple witnesses of the August shooting at 1Oak, and while they're confident they've identified the suspect responsible for shooting Suge and 2 others -- they still don't have enough evidence to arrest the suspect.

As we told you .... it's been hard for investigators to get witnesses to open up -- par for the course after a Suge-involved shooting -- and that includes Suge. We're told L.A. County Sheriff's investigators are still looking for that golden witness to come forward so they can make the arrest.

Read more: http://www.tmz.com/2014/10/12/suge-knight-shooter-1oak-vma-investigation/#ixzz3G5htrbJ3