Why where Biggie and Tupacs killings never solved ,when i was obvious WHO KILLED THEM ?

Tupac clearly got shot by one of the guys in that fight at the Vegas Hotel,Biggie was clearly shot by Suge Knight and the LAPD.Polica had found the get a way car in Biggie's murder in Suge's garage.Also how it possible in a crowded street and after party that no one would see who shot whoThis is not J.F.K being shot from a hidden building