Emanuel K. Samson, the black man suspected in a 2017 mass shooting at an Antioch church, went there “with the intent to murder a minimum of 10 white churchgoers,” a prosecutor said Monday.

During opening statements in the trial against Samson, Deputy District Attorney Amy Hunter said he left a note on the dashboard of his vehicle explaining his plans to retaliate for a 2015 church shooting in Charleston, South Carolina, when white supremacist Dylann Roof killed nine black worshipers.

The note said "Dylann Roof is less than nothing," and referenced "the blood that 10 of your kind will shed ... in terms of vengeance," according to portions Hunter read out loud in court.

Police had previously described the note in vague terms, but hadn't said if it explained a potential motive for the mass shooting at the Antioch church.

Police say Samson fatally shot Melanie Crow as she was walking through the Burnette Chapel Church of Christ parking lot after Sunday service on Sept. 24, 2017, and then shot and injured several others. He was indicted on 43 counts, including first-degree murder, aggravated assault and civil rights intimidation.

Prosecutors are seeking an enhanced sentence of life without parole. The death penalty is not on the table in this case.

Prosecutors had called 15 witnesses by Monday afternoon, among them police officers, witnesses and victims — including the church's minister and the man who tackled the suspect.

Throughout the day, their testimony shed light on a horrific crime that shattered the peace of a routine Sunday service and sent worshipers running from the church's worship space soaked in blood.

Responding officers described pandemonium so intense they didn't bother putting on bulletproof vests before running in to help victims.

Victims recalled collapsing to the ground as they saw blood pooling around them.

Witnesses remembered seeking cover as they worried their friends and family might be dead.

Church members from Burnette Chapel filled the benches of Courtroom 6C to listen, wrapping their arms around each other as gruesome memories were revived in court.

Samson watched the proceedings quietly from the defense table, wearing a gray suit and purple tie, his eyes cast down.

Trial brings new details into focus

Lawyers gave a broad outline of their evidence during opening statements, presenting the clearest picture yet of a case that has been shrouded in secrecy for months.

Hunter's opening for the state emphasized the planning that she said went in to the shooting — she said "a mountain of evidence" supported her assertion that the shooting was premeditated.

She pointed out that Samson had attended Burnette Chapel and knew the people there. She drew attention to the mask and black jacket police said he had on, which made him unrecognizable.

She showed jurors a picture of the T-shirt investigators said he wore underneath, which showed gun targets shaped like people. And she described multiple guns and ammunition police say Samson brought with him to the church.

Hunter suggested more people would have been hurt if "true-life hero" and church member Caleb Engle hadn't intervened and tackled the shooter. She said Samson had reloaded his gun just before Engle stopped him.

“If not for Caleb Engle perhaps we would have more than one count of premeditated murder,” Hunter said.

Samson's attorney contests alleged motive

Samson's defense attorney Jennifer Thompson did not dispute the fact that he opened fire on the church, killing Crow, but she said "the intent is not the way the state says.”

Thompson said Samson's motive was suicide.

"What this case is about is about a man who was very sad, very suicidal," she said. “He wanted to die."

She told jurors about fighting in Samson's household, where his girlfriend was pregnant with their daughter. She pointed out that Samson didn't take the powerful AR-15 rifle he had in his SUV into the church. She mentioned a text message Samson sent to a potential employer saying, "suicide lol."

Thompson said the fact that Samson shot indiscriminately, and didn't take advantage of multiple opportunities to kill additional victims, supported her argument that he was not focused on hurting others.

Thompson did not dispute the fact that Engle was a "hero" for tackling Samson in the midst of the shooting. She said Samson shot himself after Engle tackled him in an effort to kill himself.

Multiple questions from prosecutors and defense attorneys seemed tailored to determine if Samson's actions were premeditated or spontaneous. The difference could shape the severity of the verdict.

'This is the dress I was shot in'

Much of the day Monday focused on first-person accounts of the shooting, from Engle, Minister Joey Spann, police officers and others.

Witness Joyce Leach, who used a walker, remembered rolling under a pew “curled up into a little knot” until the gunfire stopped

Her daughter Alecia Leach was waiting in her car in the parking lot when gunfire began. She recalled locking eyes with the shooter, who was wearing a mask, mirrored sunglasses and a black jacket. She saw him advance "in slow motion" and called his movements "very deliberate."

“I thought he was going to come around the car and kill me,” Alecia Leach said. “I didn’t know what to do.”

She drove away frantically and flagged someone down. Her voice shook as she recalled her urgent plea.

“Please call 911," she remembered saying. “He’s killing everybody.”

Catherine Dickerson, who attended Burnette Chapel and was talking to Alecia Leach when the gunshots started, remembered running. For about 20 minutes, Dickerson described the shooting.

Then Dickerson made a soft-spoken announcement.

“This is the dress I was shot in,” she said.

She stepped down from the witness stand and lifted the hem of her leopard-print dress to show the jury the bullet wound in her left leg.

Details about the case have been scarce leading up to the trial.

Judge Cheryl Blackburn sealed the case file based on the high profile of the shooting. Court check-ins that are typical in most cases haven't been handled in public. And public hearings have been announced just hours beforehand instead of days or weeks ahead of time, as is customary.

At a hearing in April, Samson's defense attorney questioned a psychiatrist who said Samson heard voices, hallucinated, had intense mood swings and suffered from "schizoaffective disorder bipolar type."

Reach Adam Tamburin at 615-726-5986 and atamburin@tennessean.com. Follow him on Twitter @tamburintweets.