Hamilton Jr, who is the son of former IndyCar driver and Indianapolis 500 competitor Davey Hamilton, was arrested on Saturday in West Palm Beach Florida.
The 21-year-old is accused of breaking into his ex-girlfriend's hotel room with a knife after luring her to the state by posing as the owner of a vodka company, who was interviewing her for a brand ambassador role.
Hamilton Jr allegedly enlisted a chauffeur to bring the young woman to the hotel and paid for the room. When she arrived, he reportedly sent her a text saying 'get ready', prompting her to get in the shower.
According a West Palm Beach Police Department probable cause affidavit seen by USA today, Hamilton Jr then crept into the room and ripped down the shower curtain while holding a 10-inch knife.
He then forced the alleged victim to sit on the bed before interrogating her and accusing her of cheating on him, the affidavit says.