WAXAHACHIE -- Ellis County Sheriff Johnny Brown resigned Wednesday before pleading guilty to a misdemeanor assault charge. He was then fingerprinted and booked into the Ellis County jail he once oversaw, where he will serve a one-day sentence.

He also surrendered his Texas Peace Office License, effectively ending his career in law enforcement.

The assault happened at a Midlothian Whataburger on New Year's Day, when Brown walked in to find his brother, 59, in a fight with three younger men.

One of the men knocked Brown's brother to the ground, said a statement Brown's attorney issued shortly after the fight.

Brown stepped in, hitting one of the men, Matthew Longoria, eventually leading to his resignation.

"When you’re elected as sheriff, you swear to protect the people of your county, and I just feel like he didn’t do his job that night," said Longoria. "We’re just grateful for the cooperation he took, the responsibility."

Brown did not address reporters, instead issuing a statement through his attorney, Richard Carter.

"I offer my most sincere apologies to any and all who I may have hurt or disappointed. As can be seen by the actions I have taken to make things right today, I care more for the office I held, my coworkers and fellow public officials, the citizens of Ellis County, and respect for the law than to continue a battle that consumes time, money and detracts from the mission of protecting and serving," said Brown's statement in part.

The Class A misdemeanor carries a sentence of up to one year, and up to a $4,000 fine. Both sides agreed to a one-day sentence and a $500 fine, as part of Brown's plea deal.

Brown had been in office since 2009. It is unclear what his plans for the future will be.

"This is one big bad day and it’s over for him now, it’s time for him to renew his direction and walk away from law enforcement," said Carter. "He’s obviously regretting all of this that happened. If we look at another twist of events, had he not been hungry for a burger, he might have been in another place."

The case against Brown's brother is still moving through the courts.