Democratic donor and political activist Ed Buck was charged in a federal criminal complaint Thursday in connection to a man who died from overdose in Buck's apartment in 2017.

Buck, 65, was arrested Tuesday on state charges after an unidentified man survived a methamphetamine overdose in his apartment on Sept. 11. He is accused of injecting the man with the drug at his apartment.

This is the third overdose that has been connected to Buck and his apartment in recent years. Gemmel Moore, 26, died in July 2017 and Timothy Dean, 55, died in January.

Both deaths were ruled as an accidental overdose of crystal methamphetamine.

Buck was named in a federal criminal complaint that charges him with one count of distribution of methamphetamine resulting in Moore's death, according to the United States District Court for the Central District of California.

U.S. Attorney Nick Hanna said Thursday that Buck was transferred to federal custody, where prosecutors will ask for him to be held without bail until trial.

“The criminal complaint alleging Mr. Buck caused the death of Mr. Moore is supported by a 21-page affidavit that outlines a disturbing pattern of Mr. Buck soliciting men for sex in exchange for drugs and money,” Hanna said.

The complaint includes allegations from nine victims who said that Buck either administered drugs to them or strongly encouraged them to ingest drugs in exchange for sex.

Witnesses said that Buck gave Moore drugs and money in exchange for engaging in sexual activities, according to the complaint. Text message details suggest that Buck brought Moore to Los Angeles from Texas for the sole purpose of engaging in sex, the complaint said.

Buck told investigators after Moore's death that he did not see Moore inject the methamphetamine that resulted in his death, according to the complaint.

He also said he and Moore were watching television when Moore became hot to the touch and eventually became unresponsive, which led Buck to call 911, the complaint said.

Buck faces a mandatory minimum sentence of 20 years in prison and a maximum life sentence on the federal charges against him.

The 65-year-old donor already faces one felony count each of battery causing serious injury, administering methamphetamine and maintaining a drug house, filed by the Los Angeles County district attorney’s office earlier this week.

Los Angeles County District Attorney Jackie Lacey said that the federal charge against Buck allowed for evidence to be used that was otherwise inadmissible for a first-degree murder charge, including testimony by Moore's mother.

"For instance, we had to prove Mr. Buck intentionally injected someone, that was difficult given that no one came out of that alive," Lacey said. "We had to prove that he did it with reckless indifference to life. We’d have to prove on a first-degree murder charge that he did it with the intent of murdering someone."

Through attorney Seymour Amster, Buck has repeatedly denied having any role in the deaths, NBC Los Angeles reported. Buck was scheduled to be arraigned Tuesday, but Amster asked for a delay until next month.

Moore's family has accused Buck, who is white, of preying upon black gay men.

In a wrongful-death lawsuit filed in February, LaTisha Nixon, the mother of Moore, claimed that Buck bought a plane ticket for her son to travel from Houston.

When Moore arrived in Los Angeles, he went straight to Buck's apartment, the lawsuit alleges. Once there, Buck allegedly injected him with crystal methamphetamine. Nixon has said her son never used the drug. Nixon accuses Buck of wrongful death, sexual battery, assault, battery, negligence, civil rights violation, hate violence and drug dealer liability.

Amster rejected the accusations that his client wasn't charged previously based on the race of Moore and Dean, saying instead that this is the first time prosecutors felt there was evidence to file a case.

"We do not feel that race played any part of this case before it was filed or when it's been filed, and that is the most important thing here," Amster said.