David Orpin clubbed a man so severely that when police found the body, they thought the bloody skull fractures were caused by a bullet that had entered on one side of the head and exited on the other, Deputy Prosecutor Scott Spallina said Tuesday in his opening statement of Orpin’s murder trial.

Orpin, 60, is on trial in state court for the beating death of 62-year-old Arthur Martinez in October 2010 in a church parking lot in Manoa.

Police found Martinez’s body on Oct. 27 after Orpin went to Honolulu Police Department headquarters, asked for a drink of water and said he probably needs to be arrested for murder, said officer Julian Tanioka, who was on duty at the security post.