By Matt Sepic, Minnesota Public Radio News

A judge on Monday ordered a mental competency exam for the man charged with carrying out a mass shooting last month in Buffalo, Minn.

Gregory Ulrich, 67, is charged with murder and attempted murder as well as firearms and explosives charges in the Feb. 9 attack at an Allina Health clinic.

Investigators say Ulrich was angry that doctors had cut off his supply of opioid painkillers.

Lindsay Overbay, a 37-year-old medical assistant at the clinic, was killed and four of her colleagues were injured.

Judge Catherine McPherson ordered Ulrich to undergo a psychological exam to determine if he can cooperate in his defense.

Prosecutors charged Ulrich in 2018 with violating a restraining order that an Allina physician had obtained. But authorities dropped that misdemeanor charge after a psychologist found that Ulrich was not competent to proceed.