With jury selection underway in Tupac Shakur's murder trial, Reggie Wright Jr. is hopeful that the truth will finally come out.

We got Death Row Records' former head of security to sit down with us ... and he's hoping the prosecution will get some answers, especially after Duane "Keefe D" Davis has been pointing the finger at him.

Keffe D -- who's on trial for Tupac's murder -- has been tried to pin the rapper's death on Reggie, claiming he's the one who orchestrated the hit.

But Reggie, who's going to be a witness for the prosecution, tells us he thinks this trial is going to debunk some big theories while confirming some other things.

He's maintaining his innocence and says he's not sweating the speculation ... check out our interview to find out why!