Shelley Davis sat upright on the witness stand in an Orleans Parish courtroom for more than three hours Wednesday night, resting a palm on her thigh as she cordially explained why she pumped seven bullets into Morris “Ice Man” Smith one December afternoon in Hollygrove, including two shots to the head.

“He snatched my purse, telling me, ‘You gonna give me money.’ I said, ‘I don’t owe you any money.’ I grabbed my gun and started shooting at Ice Man,” Davis testified.

She said she fired while running away, afraid for her life.

“I know I had a gun in my purse, and if he would have gone in my purse he woulda got hold of my gun and God knows what he would do to me,” she said. “I went in the back of my purse and I shot him. I kept shooting him. I was really scared. ... That’s why I kept shooting as I was running. Once I started shooting, I didn’t stop shooting.”

An Orleans Parish jury didn’t buy her story, deliberating for less than two hours before convicting Davis of second-degree murder Thursday afternoon in the Dec. 12, 2012, daytime slaying outside her aunt’s Olive Street home.

Davis, 24, sat quietly at the defense table, her mouth slightly agape after Criminal District Court Judge Keva Landrum-Johnson read the verdict.

During the three-day trial, prosecutors argued that Davis’ gentle demeanor masked a violent core that was activated at the behest of her beloved older brother, Eric “Fresh” Davis, who had earlier robbed the 275-pound Smith.

The jury heard a recorded phone call in which Fresh, behind bars at the time, bad-mouthed Smith and told his sister, “You got to do that then, dog.”

The response: “I’m tired of playing with dude, man. That’s a done, love ... real talk.”

On the stand, Davis claimed that she hardly knew Ice Man but that a few weeks before she shot him, he had jumped out of a car, reached for a weapon and cursed her out on the street, halting only when a friend got in the middle.

On Dec. 12, 2012, she said, Smith approached her outside her aunt’s house and started tugging at her purse, demanding payment of the money her brother had stolen.

Other witnesses claimed that Davis had made it known she meant to get Smith, though she claimed on the witness stand that she never issued any such threat. She said that after the shooting she ran home, turned off her phone and stayed in the house for a month.

Davis, who lived in Hollygrove, turned herself in to authorities three months later, in February 2013.

She sought to explain away the phone call with her jailed brother, testifying that she meant only that she was talking about his pending charge, “that he was coming home.”

And she offered her own interpretations of what prosecutors portrayed as damning social media posts, including an Instagram profile page declaring, “Keep it real and giv em ah dome shot!” and “Get in line or get lined up.”

Davis called them simply the musings of her favorite gangsta rappers.

Photos on social media show her brandishing a pair of 9mm Glock semi-automatic pistols, the same weapon Davis said she’d bought after the earlier altercation with Smith and stashed in her bag. Davis said she was merely posing, thinking it was cool, and had never fired a weapon before shooting Ice Man.

“This is her,” prosecutor Karen Lansden told the jury in her closing argument. “She’s not posing for a makeup show. This is who she is.”

Lansden and prosecutor Kevin Guillory argued that Davis first shot Ice Man in the leg, bringing him down, then shot him in the back and head.

The idea that Davis was running in fear as she fired, Lansden said, contradicted the testimony of witnesses to a daylight shooting with several people around.

“Not only did she have the balls to shoot him twice in the head, but she shot a man who was on the ground six times in the back,” Lansden said. “She didn’t care who saw her. She didn’t care because Morris Smith was getting what was coming to him. He was gonna talk (smack) on her brother? Well, she was going to take care of that. Because, as she told her brother, ‘It’s a done.’ ”

Defense attorneys David Capasso and Bradley Egenberg argued in vain that the prosecution’s focus on Davis’ social media posts was a smokescreen to divert the jury’s attention from a case of self-defense.

To the jury, Egenberg called the witnesses in the case “nothing but a parade of convicted felons” and accused prosecutors of “trying to distract you from the only moment that really matters: the instant when Shelley shot Ice.”

They portrayed Davis as a young woman who kept to herself, steering clear of trouble in a neighborhood where trouble found her.

“What the DA has done is present a menu full of red herrings,” Egenberg said.

The jury of eight women and four men disagreed.

Landrum-Johnson set a July 16 sentencing date for Smith, who faces a mandatory life prison sentence.

Follow John Simerman on Twitter, @johnsimerman.