Boston Marathon bombing suspect pleads not guilty

Meanwhile, federal prosecutors weighing whether to pursue the death penalty for Tsarnaev

Boston Marathon bombing suspect Dzhokhar Tsarnaev has pleaded not guilty to 30 counts including use of a weapon of mass destruction to kill.

He entered the plea today in federal court in Boston.

For first one, he leaned toward a microphone and said, "Not guilty," in a Russian accent. He then said not guilty repeatedly about a half-dozen more times.

Federal prosecutors are weighing whether to pursue the death penalty for the 19-year-old Tsarnaev.

Authorities say he and an older brother, Tamerlan, planted two bombs, which killed three people and wounded more than 260 at the April 15 marathon. The older brother was killed three days later following a shootout with police. Dzhokhar Tsarnaev was later found hiding in a boat in a suburban backyard.

The arraignment marks his first public appearance since he was arrested April 19.