Caro Quintero was arrested after a sniffer dog named Max found him hiding in brush in the town of San Simon in Sinaloa state during a joint operation by the navy and the attorney general’s office, a navy statement said. The site was in the mountains near Sinaloa’s border with the northern border state of Chihuahua. Mexico’s national arrest registry reported the time of Caro Quintero’s arrest at around noon. There were two outstanding arrest warrants for him as well as an extradition request from the US government. A very brief segment of video released by the navy showed Caro Quintero – his face blurred – dressed in jeans, a wet blue shirt and a baggy khaki jacket being held in both hands by men in camouflage uniforms holding assault rifles. A Navy Blackhawk helicopter carrying 15 people crashed near the coastal town of Los Mochis at the same time, killing 14 of those on board, the navy said in a statement. Available information indicates that he suffered an “accident,” the cause of which has yet to be determined, the statement said. The arrest came a few days after Mexican President Andres Manuel Lopez Obrador met with Joe Biden at the White House. “This is huge,” White House senior Latin America adviser Juan Gonzalez said on Twitter. Caro Quintero, from La Noria, Sinaloa, is perhaps best known as one of the co-founders of the Guadalajara cartel. The group’s heyday was in the 1970s and 1980s, when it mainly trafficked cocaine, heroin and marijuana from Mexico to the US. One of the group’s hitmen – or “hitman” – was Joaquin “El Chapo” Guzman, who founded the violent Sinaloa cartel but is now in prison. Caro Quintero was once sentenced to 40 years in prison for the 1985 kidnapping, torture and murder of Drug Enforcement Administration agent Enrique “Kiki” Camarena. Caro Quintero believed that Camarena was responsible for a raid on a marijuana plantation the previous year. In 2013, a Mexican appeals court ruling freed Caro Quintero after 28 years in prison. US authorities and Mexican prosecutors were outraged. The Supreme Court overturned the decision. But Caro Quintero had gone into hiding. U.S. officials have since accused him of assuming a leadership role in the Sinaloa cartel after El Chapo’s fall, while also running his own organization in the same region. Mike Vigil, the DEA’s former head of international operations, said, “It’s probably one of the most significant arrests of the last decade in terms of significance for the DEA.” Before Caro Quintero’s reported arrest on Friday, the US government offered a reward of up to $20 million for information leading to his arrest. Caro Quintero, who last year lost a final appeal against extradition to the United States, will be extradited as soon as possible, another Mexican official said. While 69-year-old Caro Quintero is no longer considered a major player in international drug trafficking, the symbolic impact of his arrest is likely to be significant on both sides of the border. Mexican security expert Alejandro Hope said the arrest indicated significant cooperation between the two countries despite recent security clashes. “This type of arrest is unthinkable without the involvement of the DEA,” he said. Mexico’s reluctance to extradite Caro Quintero to the United States before his release has always been a source of tension between the two countries. A US official said Washington was very keen to extradite him. “This will hopefully begin to mend the frayed relationship between the United States and Mexico in terms of combating drug trafficking,” Vigil said.