Embattled Hidalgo County Sheriff Guadalupe “Lupe” Treviño—one of the border’s most powerful law enforcement officials, whose office has been roiled with allegations of corruption—formally announced his resignation Friday.

Scandal has dogged Treviño since ICE’s Homeland Security Investigations and the FBI arrested his son Jonathan Treviño, a former Mission police officer, in December 2012. Since at least 2006, 30-year-old Jonathan Treviño had run a street-level narcotics task force called the Panama Unit in Hidalgo County. In March 2013, Jonathan and other officers associated with the Panama Unit—including five Hidalgo County deputies—were indicted for “conspiring to possess with intent to distribute” cocaine, marijuana and methamphetamine.”

For years, according to law enforcement sources, the task force had ripped off local dealers then resold the drugs for a profit. (The Panama Unit members pled guilty in 2013 and are still awaiting sentencing.) The news that the sheriff’s own son had been running a corrupt drug task force—while he lived with the sheriff—was shocking for many Rio Grande Valley residents. But it was only the beginning of the scandal that would roil the sheriff’s office.

Shortly after the Panama Unit bust, James Phil “JP” Flores, who ran the sheriff’s Crime Stoppers program, and 47-year-old warrants deputy Jorge Garza were also indicted along with Aida Palacios, an investigator with the district attorney’s office. According to federal indictments, the drug conspiracy centered on local drug dealers Fernando Guerra Sr. and his son Fernando Jr.—also indicted—who helped set up fake drug stings with the corrupt cops to rip off other local dealers and then sell their drugs.

In March 2013, I wrote about the sheriff and his troubles in a story called “The Shadow of the Son.” The sheriff, who runs one of the largest law enforcement agencies on the U.S.-Mexico border with 763 employees and a $44 million budget, had won his last re-election with more than 80 percent of the vote and had been tapped by the Department of Homeland Security as an adviser on border security. But since his son’s indictment and arrest, his 42-year career has been shadowed by allegations of corruption in his agency. Deputies and former deputies told the Observer that Treviño had forced employees to work on his campaigns or be demoted. Deputies were also forced to buy and sell tickets to fundraisers to pay off his campaign debt. Many of the deputies said that one of the sheriff’s commanders, Jose “Joe” Padilla, served as an enforcer for the sheriff, making sure that deputies carried out his wishes. In December 2013, Padilla was arrested on a seven-count indictment for drug trafficking and money laundering. He is still awaiting trial.

Throughout these many scandals, the sheriff has refused to resign. He’s continuously defended his record and said he had no knowledge of his son’s actions or the corruption in his agency. After Padilla was arrested, Treviño posted on his Facebook page: “Even though I consider him a friend and political supporter, I am not complicit in any illegalities whatsoever. People in all walks of life that know me and my reputation can attest to that.”

But last Friday the sheriff’s longtime chief of staff Pat Media retired. Rumors swirled in the Rio Grande Valley last week that Treviño would quickly follow in her footsteps. Today the sheriff alerted supporters on his Facebook page that he was indeed stepping down:

“Attached is my letter of resignation that serves as notice for my retirement. I do this with a very heavy heart but it is in the best interest of the County of Hidalgo and my family. Please take the letter and it’s contents for face value. Rumors run abound but they are rumors until they become fact. I would sincerely like to thank you for your support in good and bad times. These are the times when you find out who your true friends are. I have always counted on you and will continue to do so as you will with me…Thank You and God Bless You. Sheriff Lupe Trevino”

But the travails of the sheriff aren’t over yet. Many wonder whether the FBI is still investigating him and his agency and whether there will be more indictments. Commander Padilla’s trial will more than likely be set for the summer. Whatever comes out in the testimony will only further damage Treviño’s tarnished tenure as sheriff.