When the attorney general of the United States joined other prospective jurors in a D.C. courtroom last week, the case to be heard involved the theft of a cellphone, which is not surprising.

Theft and robbery of cellphones remain among the crimes most frequently committed in the District. These offenses often find their way into the courts.

Within the past week or so, at least a half-dozen cellphone cases have led to arrests, including one Friday night.

That incident occurred shortly after 7 p.m. in the 2400 block of Alabama Avenue SE when the victim was sending a text message while walking home, the police said.

Two robbers approached and demanded his phone. He refused to surrender it, and they beat him, grabbed his phone and his wallet, and fled.

Police said they canvassed the area and spotted two suspects, who were charged with robbery by force.

Such incidents have occurred throughout the city. Two were reported last week in or near Capitol Hill. On Monday, someone walking in the 1800 block of Constitution Avenue NE, apparently during the day, was also approached by several people who demanded his cellphone.

He also refused, was punched in the face and robbed. Police said they arrested two teenagers in that incident. The Constitution Avenue robbery occurred half a dozen blocks east of the area often considered to be Capitol Hill.

The next day, someone was walking in the 800 block of Pennsylvania Avenue SE, near Eastern Market, within the acknowledged boundaries of the Capitol Hill neighborhood. He was beaten, and his wallet and cellphone were taken.

Police said two teenagers were arrested the next day and charged with robbery by force.

(Attorney General Eric H. Holder Jr. was not chosen for a jury.)