WASHINGTON, June 27 (RIA Novosti) – A US federal grand jury has indicted suspected Boston Marathon bomber Dzhokhar Tsarnaev on charges of killing four people and using a weapon of mass destruction in the deadly April 15 attack, the US Justice Department said Thursday.

The grand jury returned a 30-count indictment against Tsarnaev, 19, whom US authorities accuse of carrying out the twin bombing near the finish line of the Boston Marathon together with his brother, 26-year-old Tamerlan Tsarnaev, the Justice Department said in a statement.

The younger Tsarnaev will also face charges of killing a police officer at the campus of the Massachusetts Institute of Technology during a frantic police chase of the two brothers in the days after the bombing.

Tamerlan Tsarnaev was killed during a shootout with police during the manhunt, while Dzhokhar suffered nonfatal wounds and was later detained.

Russian law enforcement authorities have been cooperating with their US counterparts in the investigation of the brothers, ethnic Chechens whose family roots lie in the turbulent North Caucasus region of southern Russia.

In 2011, Russia asked the US Federal Bureau of Investigation (FBI) to interview Tamerlan Tsarnaev over concerns relating to his interest in “radical Islam.” However, an FBI statement said that it “did not find any terrorism activity, domestic or foreign,” after questioning Tamerlan and members of his family at that time.

Three people were killed in the Boston Marathon attack, including an 8-year-old boy, while more than 260 were injured.