2:40 PM PT -- Cops say they have detained a man they believe to be the shooter -- 54-year-old Ronald Gasser.
Cops say McKnight did NOT have a gun at the time of the shooting.
Emergency responders tried to administer CPR but to no avail.
Ex-NFL running back Joe McKnight was murdered in a road rage shooting in the New Orleans area ... law enforcement tells TMZ Sports.
The incident occurred at 2:43 PM. Family members identified the 28-year-old at the scene.
A witness told NOLA.com ... she saw McKnight trying to apologize to another man after some sort of traffic incident.
The witness says the man then pulled out a gun and shot McKnight -- and while standing over him screamed, "I told you not to f*** with me" ... then fired another shot into his body.
McKnight was a high school phenom -- considered the best running back in the country.
He played college ball at USC. He was drafted by the NY Jets in 2010.
In a statement to TMZ Sports, the Jets said, "Joe McKnight was a loving father and a genuine, kind-hearted person. It is sad when life is taken in what appears to be such a senseless act of violence. Joe you will be missed."
Joe was currently playing for the Saskatchewan Roughriders in the Canadian Football League.
Roughriders president and CEO Craig Reynolds issued a statement saying, "We are saddened to hear of the tragic loss of Joe McKnight."
"Losing a member of our Rider family this way is an unthinkable occurrence. Our thoughts and prayers are with Joe’s family, teammates and coaches."
The couple hit up Bullets and Burgers in Vegas Saturday -- the day he turned 27 -- and they were loaded for bear. Kylie fired a Glock 17 and MP5K, while Tyga took aim with a gold .50 caliber Desert Eagle and an M16.
The firepower was so intense ... both needed someone to hold them up from the recoil.
After the bullets, they jumped on what's tabbed as the world's largest monster truck. Add burgers and fries, and that's a birthday with some serious kick.
"Teen Mom 2" star Jeremy Calvert gave a shout-out to the NRA while defending himself after posting a photo of his 3-year-old daughter holding a large rifle.
Jeremy referred to critics as idiots in his response to the backlash he received following a photo he posted with a caption, "Better watch out boys she wont miss lol haha." He also noted the gun was not loaded.
Jeremy pressed the point, saying how secure his weapons are in his home, but adding, "you hate guns i honestly dont give a s***. "
Philadelphia Eagles' Josh Huff was arrested for gun and weed possession after he was pulled over for speeding ... TMZ Sports has learned.
According to the Delaware River Port Authority criminal complaint, the 25-year-old wide receiver was stopped on the Walt Whitman Bridge in Jersey around 11 AM after cops saw him going 25 mph over the speed limit.
Police say his car reeked of weed -- and when a cop asked him about the smell, Huff handed him a "tight vac" container of "suspected marijuana."
Cops say Huff also told them he had a handgun in the car -- which was found in the driver's side door, next to a magazine that contained "six hollow point bullets."
Huff was booked for gun possession without a permit and marijuana possession (less than 50 grams). His bail was set at $25k.
He was also charged with DUI and illegal window tinting.
Coolio pled guilty to possession of a concealed weapon but will avoid jail time ... TMZ has learned.
The rapper was in an L.A. court Wednesday where he was placed on 3 year probation and ordered to 45 days of community service. He must remain on his best behavior -- which includes not using or carrying a gun. If he does that for a year, the charge will be reduced to a misdemeanor.
TMZ broke the story ... Coolio was yanked off a plane back in September after TSA found the gun in a book bag ... one of his crew members tried to take the fall, but cops searched the bag and it wasn't hard to determine it was the rapper's.
But it wasn't all bad news in court ... before ending his hearing, the judge turned to the rapper and told him, "You've got a different little hair style ... it suits you."
The homeless man who jumped the fence at Miranda Kerr's Malibu home and allegedly stabbed her security guard was just charged with attempted murder, assault with a deadly weapon and mayhem ... TMZ has learned.
The L.A. County District Attorney charged the intruder, Shaun Haywood, with the 3 felonies after the brutal confrontation earlier this month ... ending with Haywood getting shot 4 times and a security guard stabbed in the face and arm.
As TMZ reported ... Haywood disobeyed orders to stand down after hopping a fence ... prompting the security guard to fire multiple shots. Miranda wasn't home at the time.
The after-party for a Tory Lanez concert went to hell when gunshots rang out next to the Canadian hip-hop star's tour bus -- and fans turned on him in the aftermath.
Law enforcement tells us the incident went down just after 2 AM in Lincoln, Nebraska ... when fans started arguing over who could party on Tory's tour bus after his show. Things got heated, and cops say 21-year-old Anthony Parks busted out a handgun and fired 3 shots into the air.
No one was injured though, because Parks was firing a starter pistol with blanks ... according to police. He was cited for disturbing the peace and released.
We're told Tory was interviewed by police before he got outta Dodge. He left behind some pissed off fans who were trying to get on his bus to meet him. Clearly, the gunshots didn't scare them off the scene.
The 4 rap heavy hitters were up on a rooftop in Atlanta shooting their vid for "Buy Back the Block." Everything seemed to be running according to plan until several shots rang out ... forcing the rappers to hit the deck.
A 20-year-old man has been arrested in connection with the shooting death of Tyson Gay's 15-year-old daughter ... the 4th suspect arrested so far ... cops have confirmed.
The Lexington P.D. says they believe Lamonte A. Williams was involved in the gunfight near the Cook Out restaurant on October 16th ... in which a stray bullet struck and killed Trinity Gay, daughter of the U.S. Olympic track star.
Cops say Williams and at least 3 other men opened fire on each other that night and fired multiple gunshots.