If a murderer repented, what would happen to them after they die according to the catholic church???
David had Uriah assassinated, Moses murdered an Egyptian, Paul was an accomplice at the stoning death of Stephen, and the orchestrator of the persecution of the Church, Peter cut-off Malchus' ear (some say that he was aiming for the head or neck?).
In God's eyes, forgiveness has only one caveat: sincere and contrite repentance.
As an aside, I do not believe that anyone is in heaven now, except for Christ. Thus, if a former murderer dies accepting Christ as his lord and saviour, he will fall asleep until Christ's return, where both the currently living and the dead will rise to meet him in the air.