Six University of Pittsburgh officers responded to a shooting at the Western Psychiatric Institute and Clinic within two minutes of the first emergency call. The officers, who killed the gunman, had been trained for a Virginia Tech-style campus shooting.

John Shick, 30, opened fire in the lobby of the clinic on March 8, and then tried to escape through a second-floor parking area, the  Associated Press  reports. Unable to do so, Shick returned to the lobby where he began shooting at officers as they arrived. The officers had split into two groups of three; the first three officers  returned fire and killed Shick .

Shick had two semiautomatic pistols—one of which was stolen—and a fanny pack containing plastic bags filled with medication. A spokesman declined to say whether Shick was a patient at the clinic, citing privacy laws.

Duquesne University spokeswoman Bridget Fare said that Shick was expelled from the school last November after numerous female students filed a harassment complaint against him, the  Associated Press  reports. The harassment never contained any threats or indication of violence, according to Fare, and was limited to persistent requests for dates or other social interactions.

SEIU Healthcare Pennsylvania, the union representing 200 workers at the Western Psychiatric Institute and Clinic, is now calling for a full investigatuion of the incident, the  Pittsburgh Post-Gazette  reports. Union president Neal Bisno asked that "measures be put into place to prevent a tragedy like this from ever happening again."