Updated

Julian Zapata Espinoza, the man suspected of killing U.S. immigration agent Jaime Zapata, has been extradited to face charges in the United States, the Justice Department announced Wednesday.

Espinoza, also known by the alias "El Piolin," appeared Wednesday before a federal judge in Washington, D.C., after being extradited from Mexico.

Zapata was killed Feb. 15 when his armored car came under fire in a northern Mexican region plagued by drug violence. His partner, immigration special agent Victor Avila, was injured in the attack.

A federal grand jury indicted Espinoza in April on four charges including one count of murder of an officer of the United States for Zapata's death, one count of attempted murder of an officer of the United States, and one count of attempted murder of an internationally protected person in the attempted killing of Avila, and one count of using a firearm in a violent crime causing death.

The charges were unsealed Wednesday. His next court appearance is scheduled for January 25, 2012.

Espinoza, a reported leader of the Los Zetas drug cartel, has allegedly confessed to the attack but said that the U.S. agents' armored car had been confused with one belonging to a rival gang, Mexican media reported, according to AFP.