Mexican police on Tuesday arrested a Sinoloa drug cartel leader notorious for his time as Joaquin “El Chapo” Guzman’s right-hand man. Damaso Lopez Nunez, known in the drug world as “the Graduate” for his legal skills, has more recently been on authorities’ radar for his role in battling for control of the Sinoloa cartel. He was arrested at an upscale apartment building in Mexico City early Tuesday, authorities said, and broadcast on television being escorted out by masked police officers and soldiers armed to the teeth. President Enrique Peña Nieto touted the arrest as a major victory in cracking down on the drug cartels, describing it as “another key objective in the battle against criminality” on Twitter. Authorities said three residences were raided as part of the investigation into Lopez, and at least one of his alleged associates was also apprehended. The U.S. is expected to seek extradition of Lopez, who will face accusations of money laundering and smuggling cocaine during his time as a “top lieutenant” of Guzman.