A Puerto Rican policeman opened fire and shoot fellow officers inside their police headquarters on Monday at the southern coastal city of Ponce. Deputy Candelario Rivera Guarionex had a heated argument with his coworkers that led him to start shooting.

The 50-year-old officer gunfire said two officials and a policewoman were involved in the brawl, according to Daily Mail. He first held "a female lieutenant, a male commander and a policewoman" hostage before he  killed them, Mayra Ayala, a police spokeswoman, told The Associated Press.

In the press conference, the police said Guarionex had been banned from using his weapon, but it was returned when he passed his psychological evaluation about two years ago. In fact, Ayala added they were just about to initiate a negotiation, after which he proceeded to shoot his victims.

"There are no words to describe this tragedy," Associate Superintendent Juan Rodriguez Davila told the press. However, they were still not sure why Guarionex shot his fellow men, named Lt. Luz Soto Segarra, 49, Cmdr. Frank Roman, 49 and Rosario Hernández de Hoyos, 42.

The 19-year veteran of the anti-drug division has been arrested. Also, it has been said that his vehicle was loaded with an explosive device that authorities have started to investigate, but no information was divulged as to whether this news is true. 

Meanwhile, CNN added Col. Hector Agosto had blood stains on his shirt as he told the reporters he tried to save the victims.

"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. We have to learn from this very difficult situation," he said.

In a video obtained by CNN affiliate WAPA, it revealed the devastated family at the headquarters crying and trying to console each other. Gov. Alejandro Garcia Padilla, on the other hand, has announced three days of mourning to commemorate the lives of three officers.

He told the press he was sending his unity to Puerto Rico police, adding he treated his fellow policemen as a family, and it felt like losing a real relative.

A nonprofit organization, Officer Down Memorial Page, noted that there have been 123 officers killed while working in 2015 in the United States, a lesser number compared to the 133 in 2014.

Watch the report by BNO News.