Puerto Pico Police
Guarionex Candelario Rivera shot and killed three of his fellow officers before injuring himself.PAUL J. RICHARDS/AFP/Getty Images

A policeman with the Puerto Rico police took three of his colleagues hostage before fatally shooting them at the headquarters in Ponce. The suspect, Guarionex Candelario Rivera, took Commander Frank Román Rodríguez, Lieutenant Luz M Soto Segarra and Agent Rosario Hernández de Hoyos hostage in an office on the sixth floor of the building, where he later shot them.

Police spokeswoman Mayra Ayala told the Associated Press that authorities were about to start negotiations with the 50-year-old suspect when the victims were killed.

Rivera himself suffered injuries and was taken to a hospital. Officials are yet to confirm what the actual motive for the shooting was. Governor Alejandro Garcia Padilla told reporters that the suspect was injured but declined to explain what kind of injuries the officer sustained and how they were inflicted.

"This took us completely by surprise," Colonel Hector Agosto said at a press conference. "We are a family. I am trying to stay strong." Agosto said he had tried to intervene. "Even though I am a human being like any other, I have tried to compose myself to stay firm and do what's right so that my colleagues understand that they have a leader that will guide them as I have always, on the right path."

AP reported that Rivera who worked in the anti-drug division had previously been stripped of his weapon but it was returned to him following a psychological evaluation done two years ago.

Governor Padilla has announced three days of mourning for the fallen officers.