He had no run-ins with police, was an honor roll student and had been praised for his defensive work on the junior varsity football team.

Dimitrios Pagourtzis, 17, projected a nondescript demeanor, a quiet loner who regularly wore a trench coat to school, even on scorching hot days. He had been bullied by classmates and coaches, one acquaintance said. And recently, he betrayed a growing darkness.

Dimitrios Pagourtzis

In the weeks before the shooting at Santa Fe High School, he posted a picture of a black T-shirt on his Facebook page emblazoned in white with a simple message: “BORN TO KILL.”

The signs were so subtle that Pagourtzis’s alleged attack Friday came as a complete shock.

“There were not those types of warning signs,” said Texas Gov. Greg Abbott, R. “Here the red-flag warnings were either nonexistent or imperceptible. . . . As far as arrests, criminal history, he has none. His slate is pretty clean.”

On the same day he posted the T-shirt photo, Pagourtzis uploaded a picture of a jacket adorned with several pinned symbols. In captions, he explained the significance of each: the Communist Party’s hammer and sickle representing rebellion, Nazi Germany’s Iron Cross representing bravery, the Japanese rising sun for the tactics of kamikaze pilots, the knights templar’s Baphomet for evil, and the Cthulhu from science fiction for power.

The Facebook account was quickly taken down following the shooting, but Abbott confirmed that it belonged to the alleged shooter and called it one of the few signs of any tendency to violence.

One classmate said Pagourtzis was wearing his signature trench coat and military boots Friday when authorities say he opened fire at the school, killing 10 and injuring 10 others.

Jeremy Severin, whose son was on the junior varsity football team with Pagourtzis, said his son Dustin passed Pagourtzis in the school halls five minutes before the shooting began. Pagourtzis had been teased and bullied in the past not just by fellow classmates but by the football coaches, Severin said.

“Coaches would say that he stunk, smelled like crap,” Severin said.

Juliette Rachele, 17, a senior, said Pagourtzis was best friends with her boyfriend.

She said Pagourtzis was quiet, but passionate. Funny at times, but shy outside of his group of friends.

When the school shooting in Parkland, Florida, happened, Pagourtzis seemed floored, she said, but he also cracked jokes with his friends about school shooters and their affinity for trench coats.

“We were reacting by laughing at the trench coat thing. And he ended up buying a trench coat. We thought it was just a joke. But he really liked it,” Rachele said.

Pagourtzis and his friends liked anime and heavy metal music, Rachele said. He would sometimes offer his friends rides home from school. He was also passionate about history. “The medallions he had on his coat – that’s where that came from,” Rachele said. “He liked World War II a lot. . . . He was mostly fascinated by the German side just because he liked the different guns that they had because he thought they were cool looking.”

Over the past three months, however, he seemed increasingly depressed and withdrawn, she said.

Gage Slaughter, 17, a football teammate with Pagourtzis, who was a defensive tackle, said he is “a little weird, a little quiet. … He just was very quiet, kept to himself.”

Holly Kanipes, whose husband, Mark Kanipes, is Santa Fe’s head football coach, confirmed that Pagourtzis was a member of the team. Of the alleged shooter, her husband told her “that football was one of the good things going for him. I don’t really know anything other than that.” She said her husband spent much of the day Friday talking with agents from the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives at the high school’s field house.

Kamrin Laymance, 17, also was on the football team with Pagourtzis. He said Pagourtzis had good grades and, unlike other players, was never called out by the coach for academic failures.

Laymance also noted the long, black trench coat Pagourtzis wore daily and thought it was weird that Pagourtzis often parked on the “whole other side of the parking lot,” furthest from the school.

On his Facebook page, Pagourtzis appeared to go by the nickname Dimitri and provided detailed instructions in his bio on how to pronounce his name (“di-MI-tree-oas pag-OR-cheez”).

Pagourtzis listed as an interest the U.S. Marine Corps, “starting in 2019.” Maj. Brian Block, a Marine Corps spokesman, said the service has no record of anyone with the name Dimitrios Pagourtzis appearing in their records as a Marine, Marine recruit or prospective Marine recruit.

In the Facebook account, he described himself as an atheist, and said, “I hate politics.”

Mateo Twilley-Santiago, a 15-year-old sophomore, said Pagourtzis was in his advisory class – a period devoted to making up homework. Mateo said Pagourtzis wore his trench coat almost every day, but he never saw Pagourtzis wearing the symbols he posted on Facebook. “He was really quiet,” Mateo said.

Neighbors at the Taylor Lakes Village, where the Pagourtzis family now lives, said few in the area know them well.

The normally quiet neighborhood on Friday was blocked off by police, the ATF and the FBI. Bomb squad technicians could be seen going in and out of the home for several hours. And at one point, authorities screamed warnings to reporters nearby that there could be explosives in the home.

Jayne Scarnberg, who has lived there for 20 years, said the Pagourtzis family stood out because of their children. “It’s a predominately elderly neighborhood,” she said.

One of the few times the family would interact with others was on Halloween. Every year, neighbors said, they would wonder whether they should buy just a few pieces of candy, because the only two children who would come around were Dimitrios Pagourtzis and his little sister.

In junior high, Pagourtzis was a top student, appearing regularly on the honor roll, according to lists published in the local newspaper. Neighbors said that in his youth, Pagourtzis stuck to preppy clothes – polo shirts and slacks.

Neighbors said that Pagourtzis’ mother, who goes by Maria, works as a nurse, and his father works in the maritime business and is often overseas. During holidays, the family would often play Greek music and fly the Greek flag.

Authorities said the two guns used by Pagourtzis in the school shooting – a shotgun and a revolver – belonged to his father, who legally owned them.

Pagourtzis was a member of a dance troupe at a local Greek Orthodox church. Father Stelios Sitaras, of Assumption of the Virgin Mary Greek Orthodox Church in Galveston, Texas, told the Associated Press that Pagourtzis danced with the group in an annual festival in October, and that the family had joined the local parish.

“He is a quiet boy,” the priest said. “You would never think he would do anything like this.”

Authorities said Pagourtzis wrote in journals on his computer about plans to attack the school then turn the gun on himself.

“He said that not only did he want to commit the shooting, but he wanted to commit suicide after the shooting,” Abbott said. But when the moment came, the Texas governor noted, “he didn’t have the courage to commit the suicide that he wanted.”

In the final moments of Friday’s shooting, Isabelle Laymance, a student who hid with others in a supply closet while the gunman shot up their art class, said she heard the gunman talking with approaching police.

“‘I’ll surrender, but I need y’all to talk to me. I can’t hear you, I think I’ve blown my eardrum out. Can y’all get a megaphone? Don’t get near me. I’ll come out to y’all,'” she said she heard the gunman say. “Then he said, ‘Give me a second I’m thinking,’ and while he said that, you could hear him reloading his gun. And then the cop would step closer and he would shoot. And he said, ‘Don’t get closer to me.’ ”

After several minutes, the gunman put his firearms down and went into the hallway, she said.

At a news conference Friday, investigators said that the fact Pagourtzis was apprehended alive gives them hope of understanding a motive. Many of the recent mass shooters have been notable for the missed warnings – their run-ins with police, domestic violence, delight in torturing of animals.

But with few red flags in his past and almost no indication of past violence, authorities said they remain mystified about what drove Friday’s massacre.