Police in Arizona say foul play is a “definite possibility” in the disappearance of a 19-year-old woman who vanished three weeks ago.

Kiera Bergman was last seen Aug. 4 at a Phoenix apartment complex where she left her purse, wallet and keys behind, the Huffington Post reported.

“Our investigators have their suspicions,” Phoenix Police Department Sgt. Vince Lewis told the news site. “Foul play is a definite possibility, and we’ve spoken with the family to prepare them for anything that may or may not come out as a result of this investigation.”

Bergman’s on-and-off-again boyfriend, 23-year-old Jon-Christopher Clark, claimed to be the last person to see the teen before she went missing. Clark was arrested Aug. 17 on suspicion of identity theft and forgery but isn’t considered a suspect in her disappearance.

Police said Bergman sent a strange message to her roommate, Destiny Hall-Chand, after she left her home.

“She was saying that she was going to go out with some guy she met at the store a couple days ago, which is something that’s not like her, that’s not something she would do,” Hall-Chand told news station KPHO-TV.

Anyone with information on Bergman’s whereabouts is urged to contact police at 602-534-2121.