Brown's death was the second tragedy to hit the NFL in a week. Last Saturday, Kansas City Chiefs linebacker Jovan Belcher fatally shot his girlfriend before killing himself in front of his coach and general manager.
"We are deeply saddened by the news of this accident and the passing of Jerry Brown," Cowboys owner Jerry Jones said in a statement. "At this time, our hearts and prayers and deepest sympathies are with the members of Jerry's family and all of those who knew him and loved him."
Officers conducted a field sobriety test on Brent and arrested him on suspicion of driving while intoxicated, Argumaniz said. The charge, a second-degree felony punishable by two to 20 years in prison, was upgraded after Brown was pronounced dead.
Argumaniz said Brent, who pleaded guilty to a drunken driving charge three years ago at Illinois, was being held without bond.
Brent was speeding when the vehicle hit a curb and flipped at least once, Argumaniz said. Police received 911 calls from motorists who saw the upside-down vehicle but they did not immediately have any eyewitnesses to the wreck.
Argumaniz said when officers arrived at the scene on a state highway service road, Brent was dragging Brown from the vehicle, a Mercedes, which was on fire. Officers quickly put out the small blaze, he said.
The road has a 45 mph limit.
"I can say investigators are certain they were traveling well above the posted speed limit," Argumaniz said.
Before he was taken to the jail, Brent went to a hospital for a blood draw for alcohol testing and also received treatment for some minor scrapes.
Brent, a nose guard, has played in all 12 games this season and has been a bigger presence on defense with starter Jay Ratliff battling injuries. Brent made his first career start in the season opener against the New York Giants and has 35 tackles and 11/2 sacks.
The Cowboys signed Brown to their practice squad Oct. 24, but he hasn't been on the active roster. He was released from the Indianapolis Colts' practice squad Oct. 20. Brown played in one game for the Colts, a loss to the New York Jets on Oct. 14.
Brown played for San Antonio in the Arena Football League this year. In 2011, he played for Jacksonville in the AFL and the Hamilton Tiger-Cats in the Canadian Football League. He was born and grew up in St. Louis, attending Vashon High School.
Around the league
Jets • Tight end Dustin Keller will miss New York's game at Jacksonville on Sunday because of a sprained left ankle. Keller was listed as doubtful Friday after injuring his ankle last Sunday in the Jets' 7-6 win over Arizona. He likely be replaced in the starting lineup by backup Jeff Cumberland, who has 21 catches this season.
Backup quarterback Tim Tebow, recovering from two broken ribs, was expected to be a game-time decision.
Bengals • Cincinnati activated center Kyle Cook (ankle) off the injured reserve list.