Esteban Santiago, a U.S. citizen and Iraq War combat veteran, told the FBI voices were urging him to fight for ISIS before he allegedly gunned down 11 people, killing five, at a Fort Lauderdale-Hollywood International Airport baggage claim carousel.

The shooter – whose troubled behavior had already drawn the attention of the FBI, Army, and Anchorage police – arrived Friday afternoon at the busy airport on a flight from Alaska, with the gun used in the shooting properly stored in his checked baggage, NBC News reports. Police had taken the gun the month before after the FBI encounter but returned it.

The Justice Department announced on May 1, 2018 that it will not seek the death penalty for Santiago. Instead, he will plead guilty and serve a life prison term. According to The Sun Sentinel, factors that may have prompted the decision include the fact Santiago had served in Iraq in the U.S. military, his plea, and “he fact that he went to the FBI and asked for help two months before committing the mass shooting.”

New reports accuse the gunman of “talking to ‘likeminded people’ in ISIL chatrooms leading up to airport attack.”

#BreakingNews: Gunman told FBI he was talking to "likeminded people" in ISIL chatrooms leading up to airport attack. pic.twitter.com/FtcdQXCDUE — Kara Duffy (@KaraDuffyCBS12) January 17, 2017

One report said the shooter, who lived in Alaska, had no other luggage but the gun, which federal rules allow a person to declare at a ticket counter and check under the plane but not carry on.

We're told this is the gun used by the shooter at Ft Lauderdale airport (Photo courtesy: Mark Lea) pic.twitter.com/oENsB9MP5J — WSVN 7 News (@wsvn) January 6, 2017

His flight departed Anchorage, stopped over in Minneapolis, Minnesota, and finally arrived in Fort Lauderdale, sources told NBC. Earlier reports he flew through Canada turned out to be false. CBS News gave his name as Esteban Santiago-Ruiz; in Alaska, he worked for a security company, CNN reported.

Eyewitnesses described a horrific scene in which the gunman emerged from a bathroom and randomly executed people waiting for their luggage by shooting them in the head, with “no rhyme nor reason to it,” according to NBC News. He fired through luggage and at people who were hiding, an eyewitness told the network. The Florida governor called the attack “evil” and “disgusting” on CNN. An eyewitness told WCCO-TV in Minneapolis that the calm and silent shooter acted like he was in the woods going to target practice but he was “using people as his target.”

Surveillance video obtained by TMZ shows Santiago casually walking with other travelers before pulling a gun out of his waistband and firing three times, before sprinting out of the security camera’s view. You can watch the video here.

In addition to the five deaths, six people went to the hospital with wounds. Initial estimates of eight injured were downgraded to six.

A U.S. senator, Bill Nelson, first gave the suspect’s name out live on MSNBC. The Broward County sheriff confirmed the suspect’s name in a news conference in the evening. The Sheriff’s Department said 37 people also suffered non life-threatening injuries in the evacuation process and panic after the mass shooting.

Law enforcement sources confirm to ABC News that the gunman in custody for Ft. Lauderdale Airport shooting is Esteban Santiago. — Rich Braham (@MoBetterNews) January 6, 2017

On January 7, Federal authorities charged Santiago, 26, with an act of violence at an international airport resulting in death, which could bring him the death sentence, and weapons charges. According to the federal complaint, he confessed that he planned the mass shooting and bought a one-way airport ticket.

He hasnt been charged w/material support for terrorism. Feds can add additional charges as investigation continues. https://t.co/BxQMNSYf2T — Paula Reid (@PaulaReidCBS) January 7, 2017

Santiago is a former U.S. Army Reservist, born in New Jersey, according to NBC News. The account that Santiago may have heard voices telling him to fight for ISIS – a story he allegedly gave to the FBI at the time – came from CNN. George L. Piro, the special agent in charge of the FBI in Miami, said at the evening news conference on January 6 that the investigation spans multiple states, and he confirmed that Santiago had sought out the FBI in Alaska a few months back.

“We have not ruled out terrorism,” Piro said. “Any connections, communication – anything you can imagine, I assure you, we are pursuing every possible lead.” In a Saturday press conference, the FBI said evidence points to Santiago coming to Fort Lauderdale solely to commit the attack, that he may have visited other cities first, and he will appear in federal court on January 9. “At this point we are continuing to look at the terrorism angle,” Piro said as charges were filed.

There were reports of other red flags in the alleged gunman’s behavior.

Fed law enforcement source tells me Santiago #floridaairportshooting suspect investigated multiple times by FBI and Army CID. @foxnews — Jennifer Griffin (@JenGriffinFNC) January 7, 2017

The Broward County Sheriff said that the accused gunman was not wounded in the attack, surrendered to a deputy, and is now being grilled by federal law enforcement.

Pete Williams of NBC reported that the shooter, whose roots are in Puerto Rico, served in Iraq and returned mentally unstable. The accused shooter had prior contact with the criminal justice system in Alaska after that; court documents obtained by Heavy show he was accused of trying to strangle his girlfriend but was given a deferred prosecution agreement (you can see the documents in the last section of this story).

According to NBC Miami, eyewitnesses reported that the active shooter moved methodically down the carousel in the baggage claim area, randomly shooting people, including a couple waiting for their luggage, periodically stopping to reload. Most people targeted were clustered at the front end of the carousel, said an eyewitness who told CNN that his laptop in a backpack saved him from a bullet.

Despite a subsequent panic, there is no second active shooter, and the gunman is alleged to have acted alone, the Broward County Sheriff said.

Four victims have been identified in local news reports: Terry Andres, 62, (above), a Norfolk Naval Shipyard employee from Virginia Beach going on holiday with his wife, and Olga Woltering, a great-grandmother from Georgia, who was going on a cruise with her husband. Michael Oehme, of Council Bluffs, Iowa, also died in the attack. He was also on his way to a cruise. Shirley Timmons, of Ohio, a former small business owner was among those killed. In all cases, the victims were with spouses who watched them die but survived.

A picture says a thousand words. It was a long night for everyone. Thank you to the public for your patience. #FLLshooting pic.twitter.com/nfhOV6TkN2 — Broward Sheriff (@browardsheriff) January 7, 2017

Here’s what you need to know:

1. Santiago ‘Walked Into a an FBI Office in Anchorage & Claimed He Was Being Forced to Fight For ISIS,’ Sources Told CBS

Esteban Santiago’s family and law enforcement sources say he has a history of mental health issues, NBC News reports.

CNN reported that Santiago had allegedly been hearing voices telling him to join ISIS and that he had checked into a hospital. In addition to the possible terrorism motive, according to CNN, authorities are also investigating whether there was an altercation on the flight.

According to CBS News, authorities say Santiago allegedly “had gotten in an argument on one leg of his flight from Alaska to Florida, and the second leg of the trip was on a Delta flight.” A full database check revealed no connections between Santiago and terror groups, CBS reported.

However, Iowa Congressman Steve King raised a story circulating on conservative media sites that alleged Santiago had gone by a Muslim name on MySpace 10 years ago and “and recorded Islamic religious music on the site” with one song’s name meaning “there is no God but Allah.”

Ft. Lauderdale shooter & Islamic Jihadi mass murderer, Esteban Santiago's Islamic name since 2007 is Aashiq Hammad. https://t.co/b1jKixhWpF — Steve King (@SteveKingIA) January 7, 2017

Law enforcement sources told CBS News that the FBI contact came in November 2016, when Santiago walked into an FBI office in Anchorage and told agents he was being forced to fight for ISIS. He was hospitalized in a psychiatric facility after police were called there. “He also said his mind was being controlled by the CIA to watch ISIS videos,” reported CBS News.

One of CNN’s experts suggested on television that some have interpreted the hand signal in the above photo as potentially being an “ISIS finger sign,” although that is far from proven. A 2014 report said ISIS fighters were “now using a single, raised index finger as the symbol of their cause” that refers to the tawhid, “the belief in the oneness of God and a key component of the Muslim religion.” Again, this is far from clear in Santiago’s case, and his finger signal could mean something else entirely.

Piro confirmed the FBI contact. He said in the news conference that Santiago came in voluntarily and spoke with FBI agents. “He (Santiago) clearly stated he did not intend to harm anybody. However, his erratic behavior concerned FBI agents who were interviewing him… he was taken into custody by the local police and taken to a medical facility for a mental health evaluation,” Piro said. “We looked at his contacts and did our inter agency checks and at that point” the case was closed.

ABC News reported that Santiago “worked for a security company called Signal 88 in Anchorage…In November, he showed up to the FBI’s field office in Anchorage, where he espoused conspiracy theories, including one claim the U.S. government was trying to force him to watch ISIS videos.” ABC reported that Santiago allegedly “appeared incoherent at times,” so he was referred to local law enforcement to have his mental health evaluated. (Anchorage police referred Heavy to the FBI for any questions.)

BREAKING: Family confirms this is Esteban Santiago, the alleged Fort Lauderdale Airport shooter https://t.co/BfC8GDwEsX pic.twitter.com/qnd52erJTY — NBC New York (@NBCNewYork) January 6, 2017

Family members painted a more complex picture.

“He is a regular person, spiritual, a good person,” his brother, Bryan Santiago, told NBC News, adding that he hadn’t heard from his brother in several weeks.

The shooter has U.S. citizenship and was born in the United States, in Hamilton, New Jersey, according to the Broward County sheriff and NBC News. His family roots are in Puerto Rico, and he was raised there, NBC reported.

NBC News reported that Santiago has relatives in Union City, New Jersey. He had lived in Alaska and Naples, Florida, according to public records.

According to the Mirror, the shooter “was apprehended by authorities when he stopped shooting to reload, witnesses said.”

The mass shooting sent hundreds of panicked passengers running out of the airport and onto the tarmac. Other passengers were trapped on planes for over six hours before they were allowed to leave Friday evening.

Shooting reported at Ft. Lauderdale airport in Florida Airport Evacuated pic.twitter.com/brM4vc2x4M — Darl van Dijk (@Lastcombo) January 6, 2017

Air Canada said the airline had no record of the shooter having been a passenger with that airline.

We can confirm that we have no record of such a passenger by that name, or checked guns, on any of our flights to Fort Lauderdale. — Air Canada (@AirCanada) January 6, 2017

According to NBC News, he flew on Delta Flight no. 1088 from Anchorage to Minneapolis and then on Delta flight no. 2182 from Minneapolis to Fort Lauderdale.

The Daily Beast reported that he “lived in Anchorage, Alaska from 2014 to 2016.”

Read more about Esteban Santiago in Spanish at AhoraMismo.com:

2. He Served in Iraq & Was Discharged From the Army Reserves for Unsatisfactory Performance

On going situation at Fort Lauderdale Airport where people are injured after an active shooter opened fire. ⚠ pic.twitter.com/8QNJQyuimF — Flight Alerts ⚠ (@FlightAlerts777) January 6, 2017

According to ABC Fort Lauderdale, a U.S. senator, Bill Nelson, said “the 26-year-old was carrying a military identification.”

Santiago won awards for his service in Iraq and saw combat. However, CNN said there is evidence he was not “performing to standard” in the National Guard toward the end of his service, which took place in Alaska. “Santiago was discharged in August for unsatisfactory performance,” reported CNN, which added that one of his medals was a combat action badge.

Santiago’s brother, Bryan Santiago, said Esteban Santiago lived in Puerto Rico and enlisted in the Army Reserves while there, serving for six years, including about a year in Iraq in 2011, NBC News reports.

Shots fired at FLL airport. Guy is bleeding profusely. Supposedly others are shot on the lower level at Delta Term 2. pic.twitter.com/UcL73Y8yGx — (((Maxwill))) (@MxWllSolutions) January 6, 2017

“He was pro-America,” Bryan Santiago told NBC News.

Bryan Santiago said his brother developed mental health problems after his time in Iraq, but was not diagnosed with PTSD.

He said his brother might have had a “flashback” from his military experience.

His aunt also said he had issues after serving overseas:

Santiago's aunt speaking to Telemundo: Esteban went to Iraq. When he came back he wasn't doing well. Then 6 months later, his dad died. — ｍａｒｉａ ｌｉａ (@MariaLiaCalvo) January 6, 2017

CNN reported that Santiago’s aunt said he was the youngest of five siblings and was acting strangely when he returned from Iraq. The aunt said she was sorry, sad, and “asked God to be merciful,” reported CNN. The aunt also said “He talked about all the destruction and the killing of children,” according to CNN.

Santiago was discharged as a combat engineer and his rank was private first class, NBC reports. He did own a handgun, his brother said. CNN reported that Santiago allegedly simply stopped showing up at the Guard. The Palm Beach Post reported that the National Guard gave these details of Santiago’s service:

Info from Alaska National Guard on Esteban Santiago, @FLLFlyer shooter. pic.twitter.com/2bKO9fm0R1 — Kristina Webb (@KristinaWebb) January 6, 2017

Senator Nelson also said the accused shooter used a handgun during the mass shooting.

The shooter was not injured when taken into custody, the sheriff said in a news conference. The gunman didn’t say anything while firing, according to NBC.

3. Police Say He Traveled With Only His Gun Case & Opened Fire at Random in the Baggage Area

Woltering, one of the victims who died, was a prominent member of a Catholic church in Marietta, Georgia. Her husband was also at the baggage carousel, but he was not seriously injured, reported WSB-TV. A friend from Woltering’s church wrote a Facebook post requesting prayers for her:

Similarly, Andres, the other named victim, was with his wife, but she survived. He had a birthday approaching, and his family was too distraught to talk, reported WAVY.com.

The eyewitness accounts from those waiting for their luggage were chilling.

One eyewitness told NBC Miami that he was standing in baggage claim when the active shooter walked in and started randomly shooting people, including several people in the head. He said that people were left bloodied and that people fell on each side of him.

Update: 5 ppl dead; 8 injured were taken to an area hospital. — Broward Sheriff (@browardsheriff) January 6, 2017

John Schlicher, who was returning from a cruise, said on NBC News that “it was like a shooting gallery.” He said there was no security around and the shooter reloaded and kept shooting. He told Fox News, “People on either side of me were going down, so I dropped to the ground, my mother-in-law and my wife did. The firing just went on and on.”

One witness’ wife held a scarf to a person’s wound to try to save their life, an NBC Miami reporter said.

KVIA-TV reported that the shooting occurred inside Terminal 2, which hosts Delta Air Lines and Air Canada.

“People started kind of screaming and trying to get out of any door they could or hide under the chairs,” a witness, Mark Lea, told MSNBC. “He just kind of continued coming in, just randomly shooting at people, no rhyme or reason to it.”

A scene from inside Ft Lauderdale Airport where a shooting just happened and at least 4 ppl are dead Via @C5N pic.twitter.com/XKmM1OZJpq — omar r quraishi (@omar_quraishi) January 6, 2017

Lea told the network that the shooter used a handgun with three magazines of ammunition and “went up and down the carousels of the baggage claim, shooting through luggage to get at people that were hiding.”

Lea, a financial adviser from Minneapolis, also spoke to WCCO-TV. He told the TV station, “It sounded at first like firecrackers, and then we figured out what actually was going on. There was actually a shooter,” Lea told WCCO. “People started yelling and screaming running for any exit they could.”

Lea told the television station that the shooter was firing at people like he was in the woods, and they were the targets. He saw one couple where the woman was injured and the man lying motionless, according to the Minneapolis television station.

The gunman then tossed down the gun and “lay spread-eagle on the ground,” reported MSNBC.

There were reports he had no other luggage but the weapon.

Anchorage Airport police chief confirms Fort Lauderdale shooting suspect boarded Delta flight w no other bags other than gun in a hard case — Salvador Hernandez (@SalHernandez) January 7, 2017

Eyewitness Steve Frappier told CNN’s Anderson Cooper that he “saw the shooter.” Most of the people and the victims were at the front of the luggage conveyer belt, he said. He heard more popping sounds while he was on the floor. “I was seeing people in front of me get hit. There was a man probably 10 feet away from me who was shot in the head and his wife collapsed on top of him.” The shooter also shot someone who was on the floor, Frappier told Cooper. “He said absolutely nothing…all you could hear was just the popping of the gun.”

Frappier told Cooper he was wearing a backpack, and at one point the gunman shot toward his direction. A bullet ricocheted, and he later realized the bullet had struck his laptop in his backpack. He said luggage was falling onto him too, but the laptop may have acted as a shield that saved his life.

4. Santiago Has a Child & Girlfriend in Alaska

The shooting unfolded about 12:55 p.m. Eastern Standard time in Florida. In a few minutes, it was over.

A Broward County Sheriff’s Deputy took the shooter into custody, the sheriff said at the news conference. NBC reported that the accused shooter may have shot fellow passengers, as they were the grouping of people from the suspect’s plane. The shooter used a 9mm weapon, reported CBS News.

Santiago’s brother told NBC News the suspected gunman had a girlfriend and a child.

NBC News reported that the son and his mother live in Puerto Rico.

Bryan Santiago told the news network his brother was “fighting with a lot of people” while in Alaska, including his girlfriend, and was “receiving psychological counseling.” Bryan Santiago said his brother had relationship issues.

5. The Suspect Was Accused of Domestic Violence in Alaska & Was Once Investigated for Child Porn

The relationship was indeed troubled.

The court documents, obtained by Heavy from the Alaska municipal prosecutor, alleged that a woman had reported last January that her boyfriend, Esteban Santiago, “was yelling at her while she was in the bathroom on the toilet. Santiago then forced his way into the bathroom breaking the door, and door frame in the process.”

She told authorities that he continued to yell at (word removed): “get the f-ck out b-tch, while strangling her and smacking her in the side of the head.” The complaining officer said no physical injuries were seen.

“Officers attempted to locate and contact Santiago, in multiple locations. Photographs were taken of (the accuser) and the bathroom door,” the court document reported. Heavy is not naming the accuser as she is an alleged victim of domestic violence.

A month later, in February 2016, Santiago was accused by the Anchorage municipal prosecutor of violating the conditions of his release by allegedly failing to adhere to court restrictions. “During a compliance check, APD officers found defendant at the residence (of the girlfriend) in violation” of the conditions.

The court documents alleged: “Defendant admitted he had been at the residence – and with (the girlfriend) – in violation of his conditions since he had been released from custody on or about January 17, 2016 in the pending case.”

The case did not result in conviction.

Seneca Theno, the municipal prosecutor, told Heavy of the case’s disposition, “16-278 is in deferred prosecution status. Defendant pled to both charges (courtview is incorrect) and is required to abide by bail conditions and other special conditions related to the deferred prosecution agreement (DSA). It is not clear to me whether the terms of that agreement were put on record at the hearing 3/24/16, so at this time they remain confidential. Continued sentencing hearing is scheduled for 3/28/17. The other case, 16-1478, was dismissed in exchange for the plea to the DSA in the 278 case.”

You can read the court documents here:

According to NBC Washington, “Alaskan court records show an Esteban Santiago with the same date of birth was charged with two misdemeanors last year; one count was dismissed and Santiago was due back in court on the second this coming March.”

The Daily Beast reported that an assault case “was related to domestic violence” and was “resolved in March when Santiago entered into a deferred prosecution agreement, an alternative to adjudication where a state prosecutor dismissed the charges in exchange for Esteban’s completion of requirements that are unknown.”

There was also a report that Santiago was allegedly investigated for child porn.

MORE: In 2011 or 2012, suspect was investigated for child porn, but there was not enough evidence to prosecute, sources tell CBS News. — CBS News (@CBSNews) January 6, 2017

Anchorage police told Heavy they were referring all calls to the FBI. Here’s part of the court record from Anchorage:

CBS News also reports that Santiago was once investigated for possession of child pornography, in either 2011 or 201, but there was not enough evidence to charge him. Investigators seized a computer and three weapons at that time, CBS reports.

Officials believe Santiago acted alone.

There were early reports that there might be more than one active shooter as people at the airport were told to take shelter as authorities searched for a second possible shooter. NBC Miami said some people had fainted as people ran for safety and were evacuated. There was a massive law enforcement response as authorities – from the ATF to the FBI and local police – hunted for a possible second shooter.

By later in the afternoon, the sheriff confirmed there was only one gunman, and he says that gunman was Esteban Santiago.