LOS ANGELES — One of two doctors charged in the investigation of the death of Matthew Perry is expected to plead guilty Wednesday in a federal court in Los Angeles to conspiring to distribute the surgical anesthetic ketamine. [time-brightcove not-tgx=”true”] Dr. Mark Chavez, 54, of San Diego, signed a plea agreement with prosecutors in August and would be the third person to plead guilty in the aftermath of the Friends star’s fatal overdose last year. Read More: Matthew Perry Wanted to Be Remembered for Helping Others in Recovery From Addiction Prosecutors offered lesser charges to Chavez and two others in exchange for their cooperation as they go after two targets they deem more responsible for the overdose death: another doctor and an alleged dealer that they say was known as “ketamine queen” of Los Angeles. Chavez is free on bond after turning over his passport and surrendering his medical license, among other conditions. His lawyer Matthew Binninger said after Chavez’s first court appearance on Aug.