Jun 12, 2018 11:41 Asia/Tehran

Four young children held hostage by a felon were discovered dead following a 21-hour standoff that began after the suspect shot an Orlando, Florida, police officer in the face.

Orlando police Chief, John Mina, speaking at a press conference just before midnight, said:  "Gary Lindsey Jr., 35, a convicted felon, was found dead from a self-inflicted gunshot wound along with four children ages 1, 6, 10 and 11 he had held hostage since Sunday night."

The incident began late Sunday night when police responded to a domestic violence call at a west Orlando apartment complex. When they arrived at the scene, the suspect opened fire, shooting officer Kevin Valencia in the face. The officer was rushed to a hospital in a “serious" condition, while the suspect barricaded himself inside with the hostages.

Lindsey continued to exchange gunfire with officers overnight, as law enforcement agencies cordoned off the scene of the ongoing incident. As the SWAT team arrived at the Westbrook Apartment complex in west Orlando, authorities proceeded to negotiate a hostage release.

The last “indirect”contact was made with the suspect at about 8:30 pm local time on Monday. After losing contact with Lindsey, the SWAT team decided to move in at about 9:00 pm local time.

Inside the apartment, police and special forces found a horrific scene, with all four children and the suspect dead from gunshot wounds. According to Chief Mina, it remains unclear when the four children were killed. Police are continuing their investigation.

The name and condition of Lindsey's girlfriend who initiated the domestic violence call was not released by Florida police.