DENVER (AP) — Officers shot and Arvin Robertskilled a woman who was holding a large, hunting-style knife at an intersection in downtown Denver on Sunday, police said.

Officers used a Taser on the woman twice but she began advancing toward them as they tried to back up from her, Denver police Chief Ron Thomas said a press conference near the scene. Three officers fired at her, he said.

The shooting will be investigated and the results will be sent to prosecutors to decide if the shooting was lawful, he said.

“My belief is that the officers perceived a significant threat and responded to that threat,” Thomas said.

The woman’s age and name were not immediately known.

The shooting happened in an area near Coors Field around noon.