LAKELAND, Fla. —

Someone pounded on Miguel Rivera's sliding glass door early Sunday, but when he went to investigate, no one was there.

Minutes later, gunfire erupted at his neighbor's house, where authorities say a Marine vet who thought he heard the voice of God killed four people, including a 3-month-old boy.

Rivera said he believes Bryan Riley might have killed him if he had gotten to the door sooner.

"I pray to God every day I am alive still," Rivera said Tuesday from the front porch of his Lakeland home. "I feel sad for those people. God rest their soul."

Riley, 33, is being held without bond on four counts of first-degree murder for the slayings of Justice Gleason, 40; his 33-year-old girlfriend, Theresa Lanham; their son, Jody, who was born in May; and Lanham's 62-year-old mother, Catherine Delgado, who owned the property. He is also accused of seriously wounding an 11-year-old girl and killing the family's dog.

Polk County sheriff's officials say Riley, who served in Afghanistan and Iraq, broke into two homes on Delgado's property about 4:30 a.m. Sunday, shooting his victims as they cowered in fear and begged for their lives. The baby was found cradled in his mother's arms.

At the crime scene Tuesday, sheriff's deputies carted out bags of items. The single-story, concrete block home has a smaller home in the back near a child's inflatable pool. A sign on a fence labels the property "The Compound," while another sign warns about a dog on the premises.

"They were nice people. It doesn't make sense. I can't get it through my head," Rivera said.

The girl who survived is in stable condition at a Tampa hospital, officials said. A family statement said she has already undergone four surgeries to repair 10 wounds but is alert, reading, writing and generally in good spirits. The Associated Press is not identifying her because of her age.

"She was very scared when this happened, but she just prayed during the event and knew it would be OK," their statement to WTVT-TV said. "We appreciate all the well wishes, kind words and prayers."

Gleason's mother, Pamela Freeman, declined to comment Tuesday.

Thirty miles from the shooting, no one answered the door Tuesday at Riley's home in the Tampa suburb of Brandon. The house was already decorated for Halloween, with a scarecrow and jack-o'-lanterns. Neighbors said Riley was quiet and didn't socialize, but last week he stopped John Morris' wife, who has cancer, and said, "I want to pray for you."

"It was odd. He didn't make it loud or anything. He didn't talk to us much and then all of a sudden he comes up with this," said Morris, 77.

The massacre came about nine hours after investigators say Gleason had a bizarre confrontation with Riley. Detectives don't believe Riley knew the family or others in the neighborhood, but as Gleason mowed his lawn Saturday evening, Riley pulled up in his truck.

Riley told Gleason that God had sent him to prevent a suicide by someone named Amber. Gleason and one of the other victims told Riley no one by that name lived there and asked him to leave. They called 911, but when authorities arrived, Riley was gone. A deputy searched the area but didn't find Riley.

But Riley returned. About 4:30 a.m., he arranged glow sticks to create a path leading to the victims' house in what Polk County Sheriff Grady Judd said may have been an attempt to draw officers "into an ambush."

Shooting soon began — neighbor Liberty Ulrich's security camera recorded at least four short volleys of about six to 10 shots each. A deputy in the area heard the gunfire and sounded the alarm, bringing state and local law enforcement officers to the scene. When they arrived, they found an apparently unarmed Riley outside, dressed in camouflage, and his truck ablaze.

Riley ran back into the house, where authorities heard more gunfire, "a woman scream and a baby whimper," Judd said.

Officers tried to enter, but the front door was barricaded. Judd said that when they went to the back, they saw Riley, who appeared to have donned full body armor.

Riley and the officers exchanged heavy gunfire, with dozens "if not hundreds of rounds" fired, before Riley retreated back into the home, Judd said.

Everything fell silent, until a helicopter unit noticed that Riley was coming out, the sheriff said. He had been shot once and surrendered.

Officers heard cries for help inside but were unsure whether there were additional shooters. Still, one officer rushed in and grabbed the wounded girl, who told authorities there were three dead people inside.

"I will never be able to unsee that mother with that deceased infant in her arms," Judd said. "It is a horror of the utmost magnitude."

Detectives say he confessed, telling them he was on high on methamphetamine. He told them they know why he did it. They don't.

Riley's girlfriend told investigators he was never violent but had become increasingly erratic. She said he claimed to be on a mission from God, stockpiling supplies for Hurricane Ida victims including $1,000 worth of cigars. He worked as a private security guard and had no criminal history, the sheriff said.

"This guy was a war hero. He fought for his country," Judd said. Now, "he's a coldblooded killer."

LAKELAND, Fla. — A military veteran that law enforcement officials described as a "survivalist" was responsible for a shooting that left four people dead — including an infant — and one person injured in unincorporated Lakeland, Florida, on Sunday morning.

The suspect was taken into custody Sunday after exchanging gunfire with police in a neighborhood on North Socrum Loop Road near Fulton Green Road. He's been charged with murder and attempted murder and has been denied bond.

"He killed four people this morning and tried to kill deputies," Polk County Sheriff Grady Judd said.

Officials with the Polk County Sheriff's Office said they responded to the incident at about 4:30 a.m Sunday after deputies heard rounds of gunfire in the neighborhood.

When deputies arrived on the scene, they found a man dressed in camo who ran inside a home. Judd said that man did not have a gun at the time.

According to police officials, deputies heard another round of gunfire inside a home and heard screaming inside. The deputies then made their way around the home and entered through the back.

Law enforcement encountered the suspect shortly after entering the house, and Judd said deputies and the suspect exchanged gunfire. The suspect was reportedly wearing bulletproof gear from head to toe.

Moments later, the suspect came out the front door of the house with his arms raised and was taken into custody.

No deputies were injured.

After the suspect was taken into custody, deputies made their way inside the home and found an 11-year-old girl with multiple gunshot wounds. She was airlifted to Tampa General Hospital. As of Monday morning, the girl remains in critical condition but doctors say she is "stable."

The girl told deputies there were more people dead inside the home. Deputies later found a 40-year-old man, a 33-year-old woman, a 3-month-old infant and the family dog dead. Judd added that deputies found the woman holding the baby in her arms.

In another home, a 62-year-old woman was found dead.

"It's easy to shoot innocent children and babies and people when you have a gun, and they don't. He was not much of a man," Judd said.

Judd said police shot the suspect once during the incident. Deputies transported him to a nearby hospital for treatment.

While being treated in the ER, the suspect tried to grab a Lakeland police officer's gun and fought with other officers. He was then medicated, treated and has since been released from the hospital. He remains in police custody.

Judd said the suspect, 33-year-old Bryan Riley, told deputies he took meth before the shooting and said he was a "survivalist." The shooter also allegedly told deputies, "you know why I did this."

In an affidavit, police allege that Riley denied knowing the victims. When asked for a motive, Riley allegedly told police, "because I'm a sick guy. I want to confess to all of it and be sent to jail."

Police also alleged in the affidavit that Riley admitted to "setting fire to a pick-up truck at the incident location for the purpose of creating an exit strategy" and grabbing the officer's gun at the hospital.

The suspect's fiance stated he "has been acting very strangely over the last seven days," according to the affidavit.

She told deputies he "does executive protection/bodyguard related work and after working a special detail at a church in Orlando, he believed he could speak with 'God.'"

Still, Judd said the woman had seen the suspect depressed but not violent. Judd added that Riley was a decorated Marine and served in Iraq in 2008 and Afghanistan in 2009-2010.

"At the end of the day, when you look, this guy, prior to this morning, was a war hero. He fought for his country in Afghanistan and Iraq," Judd said.

Judd added that Riley had virtually no criminal history.

Riley lives in Brandon, Florida and Judd said he isn't sure why he went to Lakeland.

Frank Pack, Riley's neighbor, said he saw the news of a shooting on Facebook earlier in the day but had no way of knowing the suspect lives across the street.

"To tell me this kid is over there doing a shooting — I can't believe it, really. I just can't believe it," Pack said.

Pack said he knows Riley's mother and describes them as "very nice people."

Pack said he's a Vietnam veteran, and his two sons have been deployed to Afghanistan in the past. He brought up the importance of mental health support for veterans.

"They used to have to go see people, talk about it," Pack said of his children. "I thought that was the greatest thing in the world. You know, you get over there, I mean I was over in Vietnam, so you know you get that stuff in there, and it's great when somebody can come along and get it out of you."

Judd said officials are working on pending charges against Riley.

As of Sunday night, the Polk County Sheriff's Office says it has not received any information regarding the 11-year-old girl's condition.

This story was originally published by Lisette Lopez on Scripps station WFTS in Tampa, Florida.