MEXICO CITY (AP) – Mexican marines were closing in on infamous drug lord Rafael Caro Quintero deep in the mountains of his native state of Sinaloa. But it was a 6-year-old bloodhound named “Max” who rousted from the undergrowth the man allegedly responsible for the murder of a U.S. DEA agent more than three decades ago. While the United States’ motivation to find Caro Quintero was never in doubt – hence the $20 million reward for information leading to his capture – there was less certainty about the commitment of Mexico President Andrés Manuel López Obrador, who had made clear his disinterest in pursuing drug lords, was less certain. Yet on Friday, three days after López Obrador and U.S. President Joe Biden met in the White House, the DEA’s most wanted target was in Mexican custody.