Lakeland, Florida - A Marine Corps veteran killed four people during a horrifying shooting spree in Lakeland, Florida on Sunday.

The suspect, whom police named as 33-year-old Bryan Riley, fatally shot a man and a woman who was holding a baby at a home near the town of Lakeland, Polk County Sheriff Grady Judd said in a press conference.

An 11-year-old girl was wounded by multiple gunshots but survived, he said, although she is now reportedly in critical condition. Another woman, as well as a dog, were killed at a different home on the property.

The attacker engaged in a shootout with police officers, but surrendered in the end, Judd said, adding that the man was wearing full combat gear, including a bulletproof vest.

Dozens, if not hundreds, of shots were fired in the exchange of gunfire with the rushed police officers. "He had everything down to first aid kits. He was ready for battle," the sheriff added.

According to initial information, Riley had served in Iraq and Afghanistan.

He shockingly admitted that the victims had begged him to let them live, but he shot them anyway. The Brandon, Florida resident had also taken methamphetamine.

Investigators found no connections between Riley and his victims, but the in the run up to the rampage, his behavior had become increasingly alarming.

According to his girlfriend, Riley was suffering from PTSD and insisted that God was talking to him. The day before the shooting, he told her that he saw a man on a lawnmower, whose daughter was about to commit suicide.

Sheriff Judd said that Riley asked one of his victims, 40-year-old Justice Gleason, if he had a daughter named Amber. Gleason said he didn't and asked him to leave, but Riley "was insistent." Authorities believe one of the women who died had been called to the scene to help resolve the situation.

No officers were injured in the shootout with Riley, who eventually surrendered. "It would have been nice if he had come out with a gun and then we’d been able to read a newspaper through him and we’d have a different conversation here this morning," Judd added.