Phoenix police said Wednesday they were searching for a suspect in the shooting of three people in an office building.
One person was severely wounded, but none of the injuries was life-threatening, Phoenix Police Public Information Officer James Holmes said.
The building houses several medical-related business.
The suspect, a white man in his mid-60s, may have fled the scene in a white vehicle, according to Holmes, who cited witnesses.
Former astronaut Mark Kelly referred to the shooting during a Senate Judiciary Committee hearing on gun violence in Washington. "There's 50 or so police cars on the scene," he said.
Kelly and his wife, former Rep. Gabrielle Giffords, D-Arizona, this month launched "Americans for Responsible Solutions," which seeks to raise money to counter the influence of the gun lobby.
Two years ago, Giffords was shot in the head by a gunman in a parking lot in Tucson.