When Paul Sampleton Sr. discovered his 14-year-old namesake face down on the floor, not breathing, his arms bound by duct tape, he noticed something was missing: his son’s prized pair of Air Jordan sneakers, stolen from the Grayson High School freshman’s feet after he had been shot three times in the head.

“My baby. I know it was over the shoes,” the senior Sampleton was heard telling a 911 operator during testimony Monday in the trial of three men charged with his son’s murder.

The defendants were motivated by greed, said Gwinnett County Assistant District Attorney Michael Morrison. A trail of text messages and bullet fragments link Sampleton’s onetime classmate, Larnell Sillah, Sillah’s uncle, Andrew Murray, and another man, Tauvaughn Saylor, to the killing, said Morrison, who painted a grim portrait of a crime more senseless than originally assumed.

The promising athlete and sneaker collector was targeted for his possessions, he said, but killed because he didn’t have as much as the suspects had anticipated.

“There wasn’t the money, sneakers and electronics in the house they expected there to be,” Morrison said in his opening statement to jurors.

As his alleged accomplices ransacked the townhouse where Sampleton lived with his mother, hoping to find more, Murray grabbed a pillow, placed it next to the teen’s head and began shooting, according to the prosecution. He was left to die in his mother’s kitchen.

The suspects made off with three flat screen televisions, an Xbox video gaming system, a computer, headphones, an iPad2, clothes and eight pairs of shoes. They left behind a gang calling card, said Morrison, using hand lotion to write, on a bathroom mirror, an acronym common to the Bloods.

“During this trial they’re going to disrespect me as a murderer,” said Murray, who acted as his own counsel before changing his mind Monday afternoon. A court-appointed lawyer will now take up his defense.

“Yeah I did stupid stuff in the past but I’m not an animal, I’m not a killer, I’m not a gang banger,” Murray said.

The attorneys for Sillah and Saylor told jurors there is no tangible proof that their clients were involved in the killing or a related burglary three days earlier.

“Not one eyewitness will place (Saylor) at that scene,” said his defense lawyer Matt Crosby. “There will also be not one bit of forensic evidence placing him at the scene.”

But prosecutors introduced a torrent of circumstantial evidence implicating Sillah, who hatched the plot along with two Grayson High classmates, and his older accomplices who were staying at the home he shared with his mother and grandparents. The classmates did not participate in the fatal burglary, prosecutors say.

Murray and Saylor, visiting from New York, took their places, Morrison said. They had come south to turn a profit on a cache of designer drugs but they had not made as much as they hoped and were stuck in Gwinnett.

Now Saylor was getting pressure from home, Morrison said. On the day before the fatal shooting, say prosecutors, he received a text from his mother saying the phone bill was due. Saylor’s reply, according to the prosecutor: “I’m about to take care of something right now.”

Earlier, in a text to his girlfriend, Saylor allegedly explained that, “If we get tips, we go for it.”

Prosecutors said they made their first move nearly a week earlier, breaking into what they thought was Sampleton’s home. Instead, they had forced their way into the next door neighbor’s residence before they were chased away by a burglar alarm, Morrison said.

The accused had arranged for a “fence,” Anthony English, to sell the stolen property from the Sampleton home, he said. Police found a Billionaire Boy’s Club sweatshirt, priced at over $100, matching the size and color of one Stephanie Stone, the victim’s mother, had purchased for her son as a Christmas present. Paul Sampleton, Jr. was killed one week before Christmas.

“Paul didn’t know anything about (his present),” Stone testified Monday. The shirt was stolen from her closet, where she had been hiding it. Her computer, along with her son’s iPad, were tracked down to a Gwinnett man who said he had purchased the items from English.

Sampleton had an infectious personality, his mother recalled from the stand. He had already made a lot of new friends at his new school. They had moved to Gwinnett from Lithonia, Stone said, because of the accreditation issues faced by the DeKalb County School District.

The strapping teen played baseball and football for Grayson High and his father often served as his coach. His father said they had planned to work out together the day of his son’s death.

He left work early after Stone called him saying she had not heard from their son. By the time Sampleton Sr. arrived it was too late.

“This is my only boy,” the anguished father told the 911 operator. “This isn’t real. This can’t be happening.”

Testimony resumes Tuesday. The trial is expected to last a month.