CHICAGO (AP) — Ovidio Guzmán López, a son of former Sinaloa cartel leader Joaquin “El Chapo” Guzmán, pleaded not guilty Monday to drug trafficking, money laundering and other charges during his first court appearance since being extradited to the United States (US) from Mexico.

Guzmán López was extradited Friday, five months after US prosecutors unsealed sprawling indictments against him and his brothers, known collectively as the “Chapitos.” The indictments laid out how following their father’s extradition and eventual life sentence in the US in 2019, the brothers steered the cartel increasingly into synthetic drugs such as methamphetamine and the powerful opioid fentanyl.

During the 15-minute arraignment, Guzmán López pleaded not guilty through a translator, standing before a judge in an orange jumpsuit and matching orange slippers, with his legs shackled at the ankles. He hunched forward as he listened to prosecutors and Judge Sharon Johnson Coleman.

A larger than usual contingent of seven security staff stood in the courtroom, with one facing the court benches and watching visitors.

Mexican security forces captured Guzmán López, known as “the Mouse,” in January in Culiacan, capital of Sinaloa state, the cartel’s namesake. His arrest set off violence that left 30 people dead, including 10 military personnel. Mexico’s army used Black Hawk helicopter gunships against the cartel’s truck-mounted .50-calibre machine guns. Cartel gunmen hit two military aircraft, forcing them to land, and sent gunmen to the city’s airport, where military and civilian aircraft were hit by gunfire.

Three years earlier, the government tried to capture him, but aborted the operation after similar violence.

The US indictments against the brothers that were unsealed in April said their goal was to produce huge quantities of fentanyl and sell it at the lowest price. The brothers denied the allegations in a letter.

“We have never produced, manufactured or commercialised fentanyl nor any of its derivatives,” the letter said. “We are victims of persecution and have been made into scapegoats.”

Several of the five charges against Guzmán López carry maximum life sentences, including conspiracy to import drugs and conspiracy to distribute them. A conviction on one of the counts, engaging in an illegal enterprise as a leader, carries a mandatory life sentence. Money laundering has a maximum 20-year sentence.

Homeland Security Adviser Liz Sherwood-Randall said in a statement Friday that the extradition of Guzmán López “is testament to the significance of the ongoing cooperation between the American and Mexican governments on countering narcotics and other vital challenges.” Sherwood-Randall made multiple visits to Mexico this year to meet with President Andrés Manuel López-Obrador, most recently last month.

López Obrador has described his country as a transit point for fentanyl precursors coming from China and bound for the US, despite assertions by the US government and his own military about production in Mexico.