Tyrone “Tee Boy” Daniel and Dion “Nupea” Johnson were second cousins and bosom buddies — so tight that as boys, they’d sleep in the same bed after their families relocated to Dallas to flee Hurricane Katrina.

Daniel would later return to New Orleans for school and college with an eye on an accounting degree while he worked full time at the Ritz-Carlton Hotel, said his attorney, Gary Wainwright.

Johnson dropped out in seventh grade, and by last year he was working at a New Orleans East car wash.

Daniel would let his cousin use his silver Monte Carlo, Wainwright said.

But by the time Daniel rolled up to the Untouchable car wash in the Monte Carlo on April Fool’s Day last year, they’d fallen out. Over what isn’t exactly clear, but a loud midday argument at the busy car wash ended with Daniel firing nine shots at his cousin, including a fatal slug that tore through his vital organs.

“He shot me! He got me in the heart!” Johnson said as he staggered, prosecutor Laura Rodrigue told an Orleans Parish jury on Thursday.

Johnson died right there off Chef Menteur Highway. Daniels left the .40-caliber handgun and ran, jumping a fence before surrendering to police three days later.

Daniel, now 21, sat at the defense table Thursday in a sport jacket and dress shirt as Wainwright argued the slaying was a case of self-defense. He told the jury of six men and six women that Johnson provoked Daniel, hurling a stool over the car’s windshield, threatening to kill him and shouting, “Smoke him.”

Daniel faces a single count of second-degree murder in a case that has riven a family whose members took sides, literally, across the courtroom gallery aisle Thursday.

He faces a mandatory life prison term if convicted in a trial expected to run at least through Friday before Criminal District Court Judge Tracey Flemings-Davillier.

Rodrigue portrayed Johnson as fearful of his cousin when he saw the Monte Carlo roll up to the car wash. “There was never any indication in any interview of any witness in this case that the victim, Nupea, posed any threat to the defendant,” she said.

Wainwright said the statements of various witnesses pointed to a shooter who fired only when he felt his life was in danger. Daniel was in the best position to know what his cousin was capable of doing, he argued.

“We don’t deny Tyrone shot his cousin,” Wainwright said. “He was peaceably detailing his car, the car that Dion had as much as he did, when all hell broke loose.”

Wainwright claimed Daniel was getting in his car to leave, fearing a physical scrape with the bigger Johnson, before the confrontation escalated.

“I’m gonna kill you,” Johnson said, according to Wainwright, before Daniel reached into the Monte Carlo for the weapon.

“His eyes were closed, his mind was locked up, his head was spinning,” Wainwright said of his client’s state of mind.

Wainwright pointed to a container of Meguiar’s tire shine that police found lying beside the Monte Carlo. The car wash didn’t use that brand. Daniel had been glossing his own wheels, a clear signal that he had arrived at the car wash intending to clean, not kill, Wainwright said.

But the witness who supposedly told police he heard the death threat from Johnson, car wash employee Allden Franklin, 26, denied it on the witness stand Thursday.

The next witness, Linetria Johnson, testified that her car was almost ready that day when the commotion began. She heard “a whole bunch of ‘Man, chills’ and ‘We got customers,’ ” she said, before the shots rang out.

Many witnesses saw the shooting or what led up to it.

Wainwright sought to exploit differing descriptions of what Daniel was wearing and what his cousin launched at the car to suggest to the jury that their accounts can’t be trusted.

He also tried to malign a police investigation that was tracked by a crew with “The First 48,” a reality TV homicide drama.

“The city of New Orleans is selling his life for a dime to make a reality TV show,” Wainwright said.

He told the jury that Daniel likely will testify in his own defense.

Follow John Simerman on Twitter, @johnsimerman.