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