(CNN) -- An alleged Mexican drug cartel operative has been extradited to the United States to face charges in the death of one U.S. Immigration and Customs Enforcement agent and the attempted murder of a second, authorities said Wednesday.
Julian Zapata Espinoza, also known as "Piolin," was indicted in April in connection with a February attack that killed ICE Special Agent Jaime Zapata and wounded ICE Special Agent Victor Avila.
The indictment was unsealed Wednesday as Zapata Espinoza made his initial appearance in federal court in Washington, ICE said in a statement. He was ordered held without bail.
Jaime Zapata was killed and Avila wounded when they were ambushed on a highway in San Luis Potosi. The two were traveling to Mexico City in an armored car with diplomatic plates. They were run off the road and attacked from two vehicles by gunmen who opened fire indiscriminately, authorities said.
It was the first time in 25 years that a U.S. law enforcement agent was killed while on duty in Mexico. Avila was shot twice in the leg, the agency said at the time.
Zapata Espinoza was arrested in February. The United States had asked to extradite him based on his "probable responsibility" in the death of Zapata.
Zapata Espinoza allegedly told authorities that the killers were "confused by the aspects of the vehicle" in which Zapata and Avila were riding. "They thought it was owned by a rival group," a Mexican official said in May.
He is charged in a four-count indictment with murdering an officer or employee of the United States; one count of attempted murder of an officer of employees of the United States; one count of attempted murder of an internationally protected person; and one count of using, carrying, brandishing and discharging a firearm during and in relation to a crime of violence causing death, ICE said in Wednesday's statement.
Zapata Espinoza's next court appearance is scheduled for January 25, the agency said.