Ed Buck, a Democratic donor and activist already facing charges in the death of one of two men who fatally overdosed at his West Hollywood apartment, now faces charges in the other.

A federal grand jury indicted Mr. Buck, 65, on Wednesday on one count of distribution of methamphetamine resulting in death for the overdose of Timothy Dean, 55, in January. Mr. Buck was charged last month in a criminal complaint with the same crime in the 2017 death of Gemmel Moore, 26 — a charge that was also included in Wednesday’s indictment.

The grand jury also indicted Mr. Buck on three other counts of methamphetamine distribution, saying that, for years, he had engaged in a pattern of giving drugs to men who performed sexual favors at his apartment.

“Buck exerted power over his victims, often targeting vulnerable individuals who were destitute, homeless, and/or struggled with drug addiction, in order to exploit the relative wealth and power imbalance between them,” the grand jury wrote in the indictment.