By Emanuella Grinberg and Joe Sterling, CNN

(CNN) -- As detectives investigate a deadly church shooting at Burnette Chapel Church of Christ in Antioch, Tennessee, a picture is starting to emerge of accused gunman Emanuel Samson.

He's a 25-year-old native of Sudan whose Facebook page is populated with gym selfies and bodybuilding poses. He worked as an unarmed security officer and had recently reinstated his license.

It remains to be seen how he ended up, as police allege, parked in the church lot as Sunday service was ending. In his possession he had two pistols, a tactical vest and three magazines of ammunition (as well as an empty one); in his car he had an AR-15 rifle in its case and a .22-caliber semiautomatic pistol.

His last Facebook post was at 10:26 a.m., about 30 minutes before he arrived at the church, according to an affidavit.

"Everything you've ever doubted or made to be believe as false, is real. & vice versa, B."

Church members knew him

Samson is charged with felony homicide and is being held without bond. He is scheduled to appear in court Wednesday.

Police say he is accused of killing one woman and injuring seven more in a shooting spree that ended when a church usher intervened. During the altercation, Samson accidentally shot himself in the chest with his own weapon, police said.

Police say they are trying to establish his motive.

Nashville police said Samson acknowledged opening fire in the church. He also told officers he had attended the church in the past.

Church members confirmed this, telling police he attended the church about two years ago but that they had not seen him in a while. They did not immediately recognize him because the gunman was masked.

Some members of the congregation, who declined to give their names because they did not want to speak for the church beyond its official statement, recalled Samson fondly. They said he was friendly to everyone, including one of the people he allegedly shot.

He made mysterious Facebook posts

Samson's Facebook account offers fragments of the image he created of himself for social media consumption. Church member William Brimm confirmed the account was Samson's.

It lists his name, Emanuel K. Samson, and another name he uses, Bulda. It says he is from Khartoum, Sudan and that he went to Smyrna High School in Smyrna, Tennessee, graduating in 2010. It also says he studied psychology at an unspecified community college. CNN has not independently verified these details.

Police initially said Samson is from La Vergne, Tennessee, but on his Facebook page he says he lives in nearby Murfreesboro.

His languages are Arabic, English and Acholi, according to the page. He lists no political views. "Your votes mean nothing," reads one post.

His favorite quotes include one from Right Said Fred's 1992 party anthem: "I'm, so sexy for my shirt ... so sexy, it hurts."

His penultimate quote before the shooting reads, "Become the creator instead of what's created. Whatever you say goes."

And, before that, at 10:18 a.m.: "You are more than what they told us."

One quote from his personal description now stands out, though it is not known when it was written.

"No need for a life story," it says. "You probably heard about me."

He quit his job as a security guard

On Saturday, the day before the shooting, Samson worked a shift as a security guard for Crimson Security in Nashville, police spokesman Don Aaron said.

He sent an email Sunday at 10:01 a.m., within an hour of the shooting, saying he appreciated the opportunity to work but would not be returning.

State records indicate Samson had held an unarmed security license between 2014-2016, Nashville police said. It had expired, and Samson had attended a class on Friday to reinstate the unarmed license.

He had past encounters with police

Police responded to two domestic calls at a Murfreesboro home involving Samson and his former girlfriend.

In January, police responded to an address listed as Samson's home in Murfreesboro. During an argument, Jeanna Ambrose told police that Samson punched her TV and broke a small figurine, according to a police report. They were fighting because he believed she had cheated on him, she told police. As she tried to leave the apartment, he demanded to speak to her and took her phone. She called police from a neighbor's home.

In March, police returned to the same home. Samson told officers he used to date Ambrose and was trying to break off contact with her but she "keeps coming around," according to a police report. He said that, after a brief conversation at the door, she started to get loud and tried to push his door open as he tried to close it. Samson told police that he was in fear because "she has struck him in the past" but said she had not threatened or assaulted him that day.

Ambrose told police she had come over to pick up some belongings and said she did not threaten or assault him. Officers helped Ambrose retrieve her belongings and told her not to return to the apartment, the report states. Samson was told that he could no longer have contact with her.

His next contact with police was on June 27. Murfreesboro Police responded to the home of Samson's father after a 911 call reporting suicidal threats. His father told police that Samson had texted him shortly after midnight saying he had a gun to his head, according to a police report. Samson's father said he tried unsuccessfully to reach his son on the phone and did not know where he was.

Police pinged Samson's phone and found him at the Nashville office of security service provider G4S, Nashville Police said Monday. A police officer met Samson at the office, where Samson told him that he was fine and not thinking of harming himself. The officer was satisfied that he was not a danger and left him.