An officer from the Puerto Rico Police Department is in custody after taking three fellow officers hostage, then fatally shooting them, officials said Monday.
The shooting, which took place in the police station in Ponce, one of the island's largest cities, is among the deadliest incident for police officers in the United States this year.
"There are no words to describe this tragedy where three colleagues have lost their lives," Puerto Rico Police Deputy Superintendent Col. Juan Rodriguez Davila said on Twitter.
Local news media has identified the shooting suspect as 19-year veteran of the department, but officials have yet to confirm the names of the suspect or of those killed.
Those killed included two high-ranking officers - a female lieutenant and a male commander - as well as a third officer, according to Edward Ramirez, a department spokesman, who said the suspect got in a verbal argument with at least one of them before the shooting began.
"The aggressor came to the room and started arguing with one of them," Ramirez said. "Then he closed the door and started shooting."
Ramirez said hostage negotiators had begun speaking with the suspect, who officials say was a member of the department's antidrug unit, when he opened fire on the hostages - one of whom returned fire and struck him in the arm.
"The aggressor is arrested, and he's in the hospital with a wounded right arm," Ramirez said. "The investigators think that he was shot by one of the officers who was killed."
Ramirez said that investigators have yet to determine a motive. One of the those killed is believed to be the shooting suspect's supervisor.