A 22-year-old Fort Lauderdale man, alleged to be one of the gunmen in the shooting death of rapper XXXTentacion, has been arrested and charged with first-degree murder.Michael Boatwright was arrested on July 5 on unrelated drug charges, according to a news release. While in jail, he was served with an arrest warrant for the first-degree murder charge. This is the second arrest in the case; Dedrick Devonshay Williams, 22, was arrested on June 20, and charged with first-degree murder, operating a vehicle without a license and a probation violation.XXXTentacion, born Jahseh Onfroy, was killed June 18 as he was leaving an upscale motor-sports shop in Deerfield Beach, Florida. Detectives say Boatwright and another armed suspect approached the rapper that afternoon in an apparent robbery, and that they are still seeking the second gunman. Williams has not been named a gunman in the case. Keyla Concepción, senior public information officer for the Broward County Sheriff’s Office, said Williams "was charged with first-degree murder for his participation in the crime."RELATED:XXXTentacion, controversial Florida rapper and singer, shot dead at 20Authorities say they are also seeking a person of interest in the case — Robert Allen, 22 — who is wanted in Broward County on a felony warrant for violating probation for possession of the drug PVP, also known as flakka, and carrying a concealed firearm. The Sun Sentinel reported last week that Allen was seen in a surveillance image from the motor sports shop on the day XXXTentacion was killed.The controversial rapper was just 20 years old at the time of his death. He had been awaiting trial on multiple domestic violence charges including aggravated battery of a pregnant woman and false imprisonment. His ex-girlfriend detailed the alleged abuse in a Miami New Times story published less than two weeks before Onfroy’s death.Following his death, XXXTentacion’s music surged on the Billboard Hot 100, with multiple songs re-entering the charts after falling off. "SAD!," a haunting and emotional electronic ballad, shot to the top spot, becoming the first posthumous No. 1 hit for a lead solo artist since Notorious B.I.G.’s "Mo Money Mo Problems" topped the chart following his death in 1997.