The premise that the CIA was involved with the murders of either Tupac or Biggie carries as much weight as the FBI having Joe Colombo killed. Keefe D blew himself up by giving interviews and admitting he passed the gun to Dre Brown who balked and leaned back into the seat as Baby Lane reached over and shot from the right back seat. Keefe D is alleged to have sold bullets from the same box as the ones that killed Tupac.
If you ask me, the biggest question is whether it was Poochie or Amir Khan and the LAPD, that killed Biggie for Suge. I don't think it's conclusive either way.