Democratic donor Ed Buck appears at a campaign event for a candidate in the California governor's race in Los Angeles on Sept. 22, 2010. AP Photo/Damian Dovarganes

WEST HOLLYWOOD, Calif. (KABC) -- Democratic donor Ed Buck, who has been subject to protests and calls for prosecution in the overdose deaths of two men at his West Hollywood home, was arrested Tuesday in connection with a third overdose, police say.Bail was set at $4 million.A bail motion from the Los Angeles district attorney's office states that Buck is "a violent, dangerous sexual predator. He mainly preys on men made vulnerable by addiction and homelessness." According to the documents, Buck personally administered "dangerously large doses of narcotics to his victims" and is "a predator with no regard for human life."Activists have been calling for Buck's arrest, believing him responsible for the deaths of Gemmel Moore, 26, and Timothy Dean, 55. Both black gay men were found in Buck's West Hollywood apartment less than two years apart. The coroner ruled that both deaths were caused by methamphetamine overdoses. District Attorney Jackie Lacey's office said Tuesday that Buck, 65, has now been charged with operating a drug house and providing meth to a 37-year-old man who overdosed last week. Investigators were seen removing evidence from Buck's home in the 1200 block of Laurel Avenue Tuesday night.Hussain Turk, the attorney for Moore's family, said his mother was "elated" to hear the news of Buck's arrest, and Dean's siblings were "extremely grateful and relieved that Mr. Buck is finally off the streets."One of Buck's neighbors said she was also happy to see Buck under arrest."The first thing that I thought when I saw the cops was, oh my gosh, a third person - a third victim," resident Caroline Serra said. "Then when I saw that it was him with the handcuffs, I was very relieved."Buck was charged with one felony count each of battery causing serious injury, administering methamphetamine and maintaining a drug house.Authorities say Buck injected the victim with meth on Sept. 11 at his West Hollywood home. The man suffered an overdose but survived.If convicted on all charges, Buck faces a possible maximum sentence of five years and eight months in state prison.Moore's mother has a civil lawsuit for wrongful death pending against Buck, which also names Lacey for failing to prosecute the case.Buck was expected in court Wednesday, but it is unclear when he will make his initial appearance.