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

The shooter, dressed in camouflage and a mask, was a man in his 20s who apparently fired at random before taking his own life, said Clackamas County sheriff’s Sgt. Adam Phillips.

There’s no known connection between the gunman and the man and woman who were killed and the young woman who was wounded. Kristina Shevchenko is in serious condition, Oregon Health & Science University Hospital in Portland said early Wednesday.