Mexico’s navy on Friday captured drug lord Rafael Caro Quintero, convicted of murdering a U.S. anti-narcotics agent in 1985, in a law enforcement coup that came at a heavy cost when a helicopter used in the mission crashed, killing 14 military personnel

Mexico captured the infamous drug lord Rafael Caro Quintero on Friday, the man who was behind the murder and torture of a U.S. DEA agent in 1985.

However, it appears to have come at a tragic cost.

Authorities say at least 14 people were killed and another seriously injured when a Black Hawk helicopter supporting the operation crashed in northern Sinaloa state.

President Andres Manuel Lopez Obrador said Mexico’s navy would investigate the cause of the crash, and that the helicopter had been supporting the kingpin’s capture.

Drug lord Caro Quintero was a co-founder of the now-defunct Guadalajara cartel, and eluded authorities for over a decade after walking out of a Mexican prison and returning to the drug trade.

The U.S. government hailed the arrest and said it would waste no time in requesting an extradition.

Sinaloa, where he was caught, is one of Mexico’s drug-trafficking heartlands.

Caro Quintero spent 28 years in prison for the brutal murder of former U.S. DEA agent Enrique “Kiki” Camarena, a notorious drug war killing that was dramatized in the Netflix series ‘Narcos: Mexico,’ and a low point in relations with the U.S.

Caro Quintero has previously denied involvement in the killing.

But then he was released in 2013 on a technicality by a Mexican judge, embarrassing the previous government.