The son of a deputy at the Montgomery County Sheriff’s Office in Alabama was charged with murder on Monday in the killing of the sheriff of a neighboring county.

The man, William Chase Johnson, 18, was charged with fatally shooting Sheriff John Williams of Lowndes County on Saturday night after the sheriff responded to a call at a gas station in Hayneville, Ala.

Mr. Johnson is currently being held at the Elmore County Jail, according to court records. The presiding judge denied Mr. Johnson’s bond, The Associated Press reported.

Sheriff Williams was a former Marine who had served in law enforcement for 40 years, the last nine years as the Lowndes County sheriff. He was the fifth law enforcement officer in Alabama this year to be killed in gun violence while on the job, Attorney General Steve Marshall said in a statement.