Joaquin Guzman Lopez, the son of Mexican drug kingpin "El Chapo," pleaded guilty to U.S. drug trafficking charges after his brother entered a plea deal in July.

Joaquin Guzman Lopez, one of four sons of the Sinaloa cartel's 'El Chapo', changes his plea to guilty, documents show.

Joaquín Guzmán López's guilty plea comes after US prosecutors pledged last May to not pursue the death penalty against him.