John Gill Commentary Mark 15:44

"And Pilate marvelled if he were already dead: and calling unto him the centurion, he asked him whether he had been any while dead." — Mark 15:44 (ASV)

And Pilate marvelled if he were already dead
For death, by crucifixion, was a slow lingering death; persons that were in their full strength hung a great while before they expired; and the two thieves, which were crucified with Christ, were not dead when he was:

and calling to him the centurion ;
who was set to watch him:

he asked him, whether he had been any while dead ;
he inquired of him, whether he was dead, and how long he had been dead.