BUFFALO, N.Y. >> The way prosecutors tell it, Joseph Bongiovanni went to work for years with a “little dark secret.”

Behind the veneer of a veteran U.S. Drug Enforcement Administration agent, they alleged, was a turncoat on the take from the Buffalo Mafia, offering an “umbrella of protection” that derailed investigations of his childhood friends, covered for a sex-trafficking strip club and even helped a connected high school English teacher keep his marijuana-growing side hustle.

In a federal trial that began this month, prosecutors portrayed Bongiovanni as a greedy racist who pocketed more than $250,000 in cash-stuffed envelopes over a decade and threw his colleagues off by opening bogus case files and encouraging them to spend less time investigating Italians and more time on Blacks and Hispanics, “n——- and s——” he was alleged to have called them. When authorities finally unmasked him in 2019, he hastily retired and wiped his cellphone clean.

“Sometimes the DEA doesn’t get it right,” Assistant U.S. Attorney Joseph Tripi told jurors. “He was able to manipulate everyone because, in law enforcement, there’s a certain amount of trust that’s inherent. He did it under the watch of supervisors who under-supervised him.”

The 59-year-old Bongiovanni has denied the counts of bribery, conspiracy and obstruction of justice that could land him behind bars for life, charges his attorney says are built on lies “so fanciful they don’t just strain credibility, they rip it apart.”

The trial is the latest gut punch to the 4,100-agent DEA, which has seen at least 16 agents brought up on federal charges since 2015, a parade of misconduct that has revealed gaping holes in the agency’s supervision.

The crimes have included child pornography, drug trafficking, leaking intelligence to defense attorneys and selling firearms to cartel associates, an Associated Press analysis found. One carried a “Liberty or Death” flag and flashed his badge outside the Capitol on Jan. 6. Another infiltrated the DEA in Chicago and helped traffickers smuggle thousands of kilos of cocaine from Puerto Rico to New York.

At least three veteran agents are serving prison sentences of a decade or longer, including one who laundered money for cartels in Colombia and spent lavishly on expensive sports cars and Tiffany jewels, and an Arkansas-based agent recorded taking a bribe inside a Las Vegas casino.

The cases, coming amid an epidemic of more than 100,000 fatal drug overdoses a year, often present yearslong headaches for the U.S. Justice Department to determine whether any investigations were tainted when rogue agents betrayed the badge.

“We should not expect to see this much crime in one law enforcement agency,” said Rachel Moran, an associate professor at the University of St. Thomas School of Law in Minneapolis. “The common thread I see here is a lack of oversight and accountability.”

The DEA declined to comment. DEA Administrator Anne Milgram is herself the subject of an ongoing Inspector General inquiry examining whether the agency improperly hired some of her past associates.

Like other DEA scandals, the Bongiovanni case underscores recurring questions about the agency’s hiring standards and ability to root out corruption. Background checks didn’t turn up Bongiovanni’s prior drug use and ties to Italian organized crime in his native Buffalo, prosecutors said, and not a single member of law enforcement was on to him until a trafficker paying for Bongiovanni’s protection was arrested by another agency. “He’s got that little dark secret,” Tripi said.

The trial, expected to last two months, is part of a broader sex-trafficking prosecution that has taken sensational turns, including an implicated judge who killed himself after the FBI raided his home, law enforcement dragging a pond in search of an overdose victim and dead rats planted outside the home of a government witness who prosecutors allege was later killed by a fatal dose of fentanyl.

Bongiovanni was raised in a tight-knit Italian American community in North Buffalo and known as a “door kicker” in the DEA, defense attorney Parker MacKay said, “not the type to sit in front of a computer.”

In his high school yearbook, Bongiovanni said he wanted to be a billionaire. But prosecutors said he went through financial struggles during his two-decade career that made him vulnerable to taking bribes.

His protection ranged from providing an “all clear” assuring trafficker friends they were not on law enforcement’s radar to leaking intelligence and opening fictitious cases that made it appear he was investigating them or relying on them as informants, prosecutors said, a sort of catch-and-kill tactic that prevented other law enforcement agencies from pursuing their own cases. This also positioned Bongiovanni to receive notice any time another agency became interested in one of the targets, a process known as deconfliction.

Bongiovanni also is accused of vouching for criminals, filing bogus reports and swiping a sensitive DEA case file on organized crime that he stored in his basement after his abrupt retirement.

Among the rackets Bongiovanni is accused of protecting is Pharoah’s Gentlemen’s Club, a strip club outside Buffalo described by prosecutors as a haven for drug use and sex trafficking. Bongiovanni was childhood friends with the owner, Peter Gerace Jr., who authorities allege has close ties to both the Buffalo Mafia and the notoriously violent Outlaws Motorcycle Club.

Prosecutors said Gerace had the agent on speed dial for advice when he needed to cover up the overdose of a stripper. The evidence includes a voicemail in which Gerace asks Bongiovanni about tracing a drug dealer’s cellphone. “Is there a way to ping it like police do?” he said, according to court records. “I just want to know if you could do that or not.”

Gerace attorney Mark Foti said his client “denies all charges and looks forward to confronting the government’s evidence at his trial.”

The long list of witnesses in the case includes dozens of federal law enforcement officers and a public school teacher of 30 years who admitted running a marijuana-growing operation while receiving confidential information from Bongiovanni.

Prosecutor Tripi said Bongiovanni had two sets of rules, one for cronies lining his pockets and another for everyone else.

“He did just enough legitimate work to avoid detection,” he said. “He almost got away with it.”