A murder trial that grew hostile inside an Orleans Parish courtroom — and outside, where fists flew on Tulane Avenue last week — ended Tuesday night with a jury convicting Tyrone “Tee-Boy” Daniel of second-degree murder in the daylight killing last year of his cousin Dion “Nupea” Johnson.

The jury of six men and six women deliberated for more than five hours before returning an 11-1 guilty verdict a few minutes after 6 p.m.

Daniel, a diminutive 21-year-old college student, slumped across his attorney’s lap, bawling in a gray sport jacket after a court clerk read the verdict.

“I’m sorry! I loved Nupea, man!” he cried, turning to the victim’s mother as she left weeping from the courtroom.

Daniel remained bent over for several minutes afterward, head pressed against the defense table before a bailiff shackled his wrists. His attorneys had argued self-defense, saying Daniel feared for his life when he reached into his car for a gun and fired on Johnson.

Criminal District Court Judge Tracey Flemings-Davillier set an Aug. 27 sentencing date for Daniel, who faces a mandatory life prison term.

The verdict came less than 24 hours after Daniel, who admitted he fired the fatal .40-caliber shot at the Untouchable carwash in New Orleans East, testified at times defiantly under cross-examination by Assistant District Attorney Laura Rodrigue.

Daniel bristled at being portrayed as a man on a violent mission, insisting instead that he feared for his life when he fired off nine rounds at the busy carwash, including a fatal shot to Johnson’s rear flank.

The five-day trial saw testy exchanges between defense attorney Gary Wainwright and Rodrigue. Family members and loved ones — divided over a cousin-on-cousin killing — tussled outside the courtroom.

On Friday, police issued summonses for what sources said were a pair of trial spectators who got into a fistfight. Derrick Johnson, 23, and Jamez Ward both were cited for disturbing the peace, an NOPD spokesman said. No weapons were involved in the incident, which followed another altercation among members of the split factions in the courthouse hallway.

The killing, Rodrigue told the jury, appeared to be over a girl.

Wainwright earlier said the two cousins were so close that they had slept in the same bed while staying in Dallas after Hurricane Katrina.

Daniel, an accounting major, felt sorry for his cousin, who had dropped out of school, and frequently lent Johnson a silver Monte Carlo to drive, Wainwright said.

Pot shots ran through closing arguments Tuesday as District Attorney Leon Cannizzaro watched from the back row of the courtroom. Rodrigue, the prosecutor, is Cannizzaro’s daughter. At one point, Daniel accused her of trying to pad her conviction rate with an eye toward succeeding her father as district attorney.

Wainwright argued that prosecutors had secured an unwarranted second-degree murder indictment against Daniel, who came armed with a gun when he drove up to the carwash where his cousin worked on Chef Menteur Highway.

Wainwright highlighted testimony from witnesses who saw Johnson hurl a stepstool at Daniel’s car during a verbal confrontation that preceded the shooting.

At least one witness said Johnson told Daniel, “I’m gonna kill you.”

Daniel also claimed to have heard one of Johnson’s fellow carwash employees say, “Smoke him.”

Wainwright said it was clear Daniel thought he was going to be killed and acted to save himself after showing up to have his car cleaned. The fact that he knew his cousin so well only bolstered the notion that Daniel was on solid ground in seeing a threat to his life, Wainwright argued.

Rodrigue pointed to witnesses who said that Daniel retreated to his car to retrieve the gun. She suggested that Daniel was furious, possibly over a dalliance between his girlfriend and his cousin.

“Ridiculous, this whole proceeding has been,” Rodrigue told the jury, referring to Daniel’s testimony and Wainwright’s aggressive defense. The witnesses in the case “got tortured, literally tortured for hours” under cross-examination, she said.

“You have to literally fear for your life” to be able to plead self-defense, Rodrigue argued, “and he’s locked in a vehicle with a gun. He went to confront Nupea. He was the aggressor. He brought on the conflict.”

Daniel, who left the gun behind and ran off after the fatal shooting, surrendered to authorities three days later.

Daniel had little choice but to argue self-defense, Rodrigue told the jury, given the number of witnesses who saw the incident.

“He came there to do something, and he did it,” Rodrigue said. “Something had come up with his girlfriend. He was going to march himself right over to that carwash and settle the situation.”

Daniel’s girlfriend left screaming from the courtroom.

Follow John Simerman on Twitter, @johnsimerman.