PORTLAND, Ore. (AP) — A suburban Portland mall remains closed while crime scene experts detail the shooting that left three people dead and one wounded and sent Santa and thousands of shoppers running.

Clackamas County sheriff's Sgt. Adam Phillips says the shooter was a man in his 20s who apparently fired at random before taking his own life at the Clackamas Town Center.

There's no known connection between the gunman and the man and woman who were killed and the young woman who was wounded.

Oregon Health & Science University Hospital in Portland says Kristina Shevchenko is in serious condition.

Phillips says Tuesday's shooting at a mall with 7,000 customers and 2,000 employees could have been much worse. Stores and police followed training from a shooting drill at the mall earlier this year.