Police arrested a 45-year-old Kapahulu man who allegedly pistol-whipped a 53-year-old acquaintance at his Kaimuki home on suspicion of first-degree robbery, kidnapping and first-degree burglary.

The suspect entered the 53-year-old man’s home at 2:40 p.m. yesterday and pointed what appeared to be a handgun at him and demanded money.

He forced the man into his room and began assaulting him with the butt of the “handgun,” police said.

The victim yelled out to his roommates for help.

Police arrested the suspect and recovered the weapon, which was found to be an air pistol.