Gary Wayne Lindsey Jr, 35, also critically wounded Orlando, Florida, police officer Kevin Valencia in a short firefight.
The children were aged one, six, 10, and 11 years old. Two of the children were his own but the other two were that of his girlfriend, who has not yet been identified.
The situation began, Mr Mina said, when Lindsey’s girlfriend had called the police to the apartment complex and said Lindsey had beaten her.
SWAT officers had been on the case all day, with reinforcements from the bomb squad and approximately 60 officers from the Orange County Sherrif’s office being called in due to working in the heat for an entire day.
Mr Mina said Mr Valencia is expected to survive after undergoing surgery, but he remains in critical condition. “We’re hoping for prayers from our community for our officer’s full recovery. It’s hard. It’s very traumatic when one of your officers is shot in the line of duty,” he said.
Officers had to evacuate the entire apartment complex in the night and police vehicles lined the entire block.
Mr Mina said that police officers had seen one of the children had been killed when they made visual contact with Lindsey, who had barricaded himself and the children in the second-floor apartment, to give him a mobile phone since his had spotty reception in the complex where the incident took place.
Hostage negotiators had spoken to him “a couple of times,” Mr Mina noted and they had reviewed floor plans for the residence in an attempt to save the children.
Officers had hoped to save the others, but by the time they entered later in the evening all had been killed and they found Lindsey dead, in a closet.
It is unclear when the children were shot, but all appeared to have died from the gunshot wounds at some point during the 23-hour standoff.
Mr Mina said Lindsey was a convicted felon and had been out on parole for an arson conviction. He had been arrested no less than four times for violating said parole as well.
Lindsey had also been arrested in the past on battery and theft charges. There is no information on how or where he obtained the firearm used or his motive.