LOS ANGELES — Federal prosecutors said Thursday that they had charged Ed Buck, a small-time Democratic donor and political activist, with a federal drug crime in the death of one of two men who died of overdoses in his West Hollywood home.
A criminal complaint also detailed a disturbing pattern in which the authorities said that Mr. Buck had exchanged drugs and money for sexual favors. There were at least 11 victims in the last two years, according to the complaint, including one who said he left Mr. Buck’s apartment after overdosing last week and called 911.
In the case of Gemmel Moore, who died at Mr. Buck’s apartment in July 2017, Mr. Buck, 65, was charged with distribution of methamphetamine resulting in death, which carries a mandatory minimum sentence of 20 years in prison, and a maximum sentence of life. He is being held in federal custody.
Of the 10 victims in addition to Mr. Moore, who was 26, nine said Mr. Buck had administered drugs to them or had strongly encouraged them to use drugs, Nicola T. Hanna, the United States attorney in Los Angeles, said at a news conference on Thursday.
Some victims told the authorities that Mr. Buck had injected them with methamphetamines without their knowledge while they were sleeping, according to the federal complaint. One victim said Mr. Buck was known as “Doctor Kevorkian,” and was “well known for compensating male prostitutes with drugs and money,” according to the complaint.
Most of the victims were black, the authorities said, fueling accusations that Mr. Buck had preyed on black gay men.
“Our investigation into Mr. Buck is ongoing,” Mr. Hanna said at the news conference, “and we may take more action as more evidence comes forward.”
The announcement of the federal charge came two days after Mr. Buck was charged by the Los Angeles County District Attorney’s Office in connection with the overdose of one of the victims. The state charges include battery causing serious injury, administering methamphetamine and maintaining a drug house.
Speaking to reporters on Thursday before the federal complaint was made public, Seymour I. Amster, a lawyer for Mr. Buck, said that “we will fight this case vigorously.”
Mr. Amster denied accusations that Mr. Buck had preyed on black gay men. “We do not feel that race played any part of this case, before it was filed or when it’s been filed,” Mr. Amster said.
Later that afternoon, Mr. Buck appeared in federal court at the Edward R. Roybal Federal Building. He was assigned a public defender, and a court hearing was set for Sept. 26. Federal prosecutors want Mr. Buck to be held without bail.
After Mr. Moore’s death in 2017, the Los Angeles County Sheriff’s Department began investigating Mr. Buck and talked to several other men who described their encounters with him, according to the federal complaint.
One man told investigators in August 2017 that he fell asleep on Mr. Buck’s couch and woke up tied to the couch, according to the complaint. The man said he believed Mr. Buck had injected him with drugs while he was sleeping.
Another man told investigators in September 2017 that he went to Mr. Buck’s home after Mr. Buck had offered him $800 to $1,000, according to the complaint. Mr. Buck gave the man cocaine and repeatedly told him to do more drugs, according to the complaint.
But no charges were filed against Mr. Buck after Mr. Moore’s death because the police could not prove “beyond a reasonable doubt that suspect Buck furnished drugs to Gemmel Moore or that suspect Buck possessed drugs,” according to documents obtained by The Los Angeles Times. It was not immediately clear whether the authorities considered charges in any of the other victims’ cases.
Then, in January, a second man, Timothy Dean, 55, died of a methamphetamine overdose at Mr. Buck’s home. The Sheriff’s Department said it would review Mr. Moore’s death and conduct follow-up interviews.
The authorities interviewed several other victims.
One man told investigators in April that Mr. Buck gave him a syringe that Mr. Buck said contained methamphetamine, according to the complaint. But, after injecting himself, the man said he believed the syringe contained a tranquilizer — he said he could not move for more than six hours.
The man said that Mr. Buck grew frustrated when he would not leave Mr. Buck’s apartment, and that Mr. Buck grabbed a power saw from a closet, turned it on and moved toward the man, according to the complaint. The man said that, driven by adrenaline, he was able to get up.
“The surviving victims’ statements gave us the break we needed,” the Los Angeles County district attorney, Jackie Lacey, said at the news conference on Thursday. “We have done and will continue to do everything legally possible to put this depraved sexual predator away.”
Mr. Buck is a recognizable figure in West Hollywood, a former model who became a fixture in Los Angeles Democratic political circles and was known for focusing on animal rights. In 2007, he made an unsuccessful bid for West Hollywood City Council.
Mr. Buck first rose to prominence in Arizona in the 1980s. Then a Republican, he led the Mecham Recall Committee, an effort to remove the Republican governor, Evan Mecham, from office. Mr. Mecham was eventually impeached, accused of fraud and perjury. Mr. Buck later became a Democrat.
Mr. Buck was not a major Democratic donor, but he handed out tens of thousands of dollars to California Democrats. After scrutiny of Mr. Buck rose this year, politicians began distancing themselves from him, with some donating his contributions to nonprofit organizations.
On Thursday, Jasmyne Cannick, a political activist and spokeswoman for the families of the men who died, said the federal charges were “a victory for our community.”
“It just goes to show that persistence and perseverance pay off,” she said.
Arit John reported from Los Angeles, and Laura Holson, Mihir Zaveri and Emily S. Rueb from New York. Jose A. Del Real contributed reporting from Los Angeles.