A second teenage suspect was arrested Tuesday in the June homicide of a 25-year-old man near Capitol Hill, in which authorities believe the victim was shot during the robbery of his motor scooter.

Police arrested Carlos Parks, 17, of Southeast, and charged him with second-degree murder in the fatal shooting of Tywayne Thompson on June 24 in the 700 block of 12th Street SE.

On Aug. 23, authorities arrested and charged Troy Q. Robinson, 18, also of Southeast, with second-degree murder in the case.

In documents filed in court last month, police said witnesses told them that two men conspired to rob Thompson of a scooter he had bought the day he was shot.