PORTLAND, Ore. (KOIN) – Oregon Gov. Kate Brown on Tuesday ordered all flags at state public institutions to be flown at half-staff in honor of the victims killed at the Fourth of July parade in Highland Park, Ill. 

The order remains in place until sunset on July 9. 

“The senseless act of gun violence that took place yesterday during a holiday celebration is horrific, and yet another sobering reminder that we must work together to bring an end to these senseless acts,” Brown wrote in a statement. 

She said she and her husband send their condolences to the families and friends of the six people who were killed in the shooting, those who were injured and the entire Highland Park community. 

Investigators said at least 39 people were injured in the attack. 

In a press conference Tuesday, the Lake County Major Crime Task Force spokesperson Christopher Covelli said the suspect, Robert E. Crimo III, used a high-powered rifle “similar to an AR-15.” 

Covelli said Crimo had planned the attack for several weeks, acted alone and disguised himself as a woman to help escape the crime scene.