There is more than one question that accrues to this subject.
1) was the person who opened the drapes the same person who murdered the assassins?
2) was the brief interim between the attempted murder and the locating of the assassin's bodies sufficient time for them to have been murdered at that location or murdered some place else and their bodies carried or drug to where they were found?
3) Why were the bodies located next to what appears to be a drainage pipe (in Texas we call that a tinhorn)? Was that their intended escape route (as someone posted above, why was the compound end of the pipe not grated or otherwise rendered impassable by a human)?
4) Of course, how did the assassins gain entry to the compound?
5) What was used to murder the assassins? A knife? A pistol with a silencer?
1. the person who opened the drapes did not necessarily have to be the same person who killed the hitters, and likely was not. The more I dwell on this question the more likely I believe it was Fredo who would have had access to the inner sanctum of the house, and he did it on Johnny Ola's orders.
2. The would be killers could have died as soon as they shot their last bullet so it sounded like a part of the actual hit. This would have been done by another member of the team who managed to escape. I also believe this person was helped by Fredo one way or another. Remember at one point Deanna was screaming something about their being right outside her window.
3. I think they were dragged to the drainage pipe, so it didn't matter if there was a grate. They were already dead. Maybe if there wasnt thats how the other conspirator got out.
4. I would think they gained access during the party, which would have been relatively easy.
