The seizure of a phone belonging to the son of Joaquin "Shorty" Guzmans deputy at the U.S.-Mexico border was an important break in the operation that led to the drug lord's capture, a senior U.S. law enforcement official said on Sunday, according to the Associated Press.
Guzman, who long ran the feared Sinaloa Cartel and was Mexico's most wanted criminal, was caught on Saturday in his native northwestern state of Sinaloa with help from U.S. agents, the AP reported.
It was a major victory for the Mexican government in its fight against powerful drug gangs and for the cause of cooperation between Mexican and U.S. security forces, according to the AP.
The phone that helped lead to Guzman's downfall belonged to the son of his deputy, Ismael "El Mayo" Zambada, who could now be in line to take over from his boss, the AP reported.
The break came when Zambada's son, Serafin Zambada-Ortiz, was arrested in November trying to cross the border from Mexico into the United States, where he faced sealed drug charges, according to the AP.
"This was one of several important turning points. But it was critical," the official said, the AP reported.
U.S. prosecutors said on Sunday they plan to seek the extradition of Guzman to face trial in the United States, according to the AP.
Robert Nardoza, a spokesman for the U.S. Attorney's office in Brooklyn, New York, said his office would request Guzman's extradition to face a variety of charges, the AP reported.
Sensitivities over the issue could mean he is more likely to face justice first in Mexico, where he still has an outstanding term to finish, according to the AP. He broke out of prison, reportedly in a laundry cart, in 2001.
The United States had a $5 million bounty on Guzman's head, the AP reported. His cartel has smuggled billions of dollars worth of cocaine, marijuana and methamphetamine into the United States, and fought vicious turf wars with other gangs across Mexico.
A spokesman for the Mexican attorney general's office declined to comment on the extradition request. President Enrique Pena Nieto's office also declined to comment, the AP reported.