<p class="css-at9mc1 evys1bk0" style="margin: 0px 0px 15px; vertical-align: baseline; color: #777777; font-family: 'Open Sans', sans-serif; font-size: 15px; background-color: #ffffff;">H-2 was a volatile, moon-faced man scarcely known outside the regional underworld. Growing up on the outskirts of Mazatl&aacute;n, the Sinaloa beach city, he became a sicario, or hit man, for the Mazatlecos, a local gang closely allied with the Beltr&aacute;ns, and later emerged as a lieutenant to H&eacute;ctor Beltr&aacute;n. After the capo&rsquo;s arrest, H-2 and his men &ldquo;were like orphans,&rdquo; a former Mexican official told me. H-2 gathered his forces in Nayarit, a state wedged among the narco strongholds of Sinaloa, Durango and Jalisco. He procured opium gum from Nayarit&rsquo;s eastern highlands and used B.L.O. connections to ship heroin and other drugs into the United States. As far as Beck and his team could tell, the H&rsquo;s seemed to have no trouble with the Nayarit authorities.</p>
<p class="css-at9mc1 evys1bk0" style="margin: 0px 0px 15px; vertical-align: baseline; color: #777777; font-family: 'Open Sans', sans-serif; font-size: 15px; background-color: #ffffff;">The task force acted cautiously on what it learned. The agents seized one big drug shipment but held back on actions that might jeopardize their surveillance. They sensed that they were onto an unusually good case. The H&rsquo;s were moving a lot of drugs and killing a lot of people. They were also careless in their communications. Even their &ldquo;dirty calls&rdquo; &mdash; those in which they discussed criminal activities &mdash; were rarely hard to decipher.</p>
<p class="css-at9mc1 evys1bk0" style="margin: 0px 0px 15px; vertical-align: baseline; color: #777777; font-family: 'Open Sans', sans-serif; font-size: 15px; background-color: #ffffff;">Beck and his D.E.A. supervisor, Scott Cahill, presented their case to the U.S. attorney&rsquo;s office for Nevada, but the prosecutors there weren&rsquo;t interested. The agents&rsquo; targets were far away, and the lawyers thought federal judges might balk at authorizing wiretaps that originated in a state court. The Justice Department&rsquo;s Narcotics and Dangerous Drugs Section also passed on the case.</p>
<p class="css-at9mc1 evys1bk0" style="margin: 0px 0px 15px; vertical-align: baseline; color: #777777; font-family: 'Open Sans', sans-serif; font-size: 15px; background-color: #ffffff;">Cahill urged his team to keep pushing. Then, in the summer of 2015, the agents got another chance to shop their case: The D.E.A.&rsquo;s Special Operations Division invited them to a closed-door gathering of federal agents and prosecutors in San Diego. The meeting was focused on Guzm&aacute;n and Sinaloa, but Beck and the intelligence analyst on his squad made a brief presentation about their little-known gang from Nayarit. As soon as they finished, a tall, broad-shouldered man hurried up to them. Cahill thought he looked like a college kid. He introduced himself as Michael Robotti, an assistant U.S. attorney for the Eastern District of New York, the high-profile judicial district based in Downtown Brooklyn.</p>
<p class="css-at9mc1 evys1bk0" style="margin: 0px 0px 15px; vertical-align: baseline; color: #777777; font-family: 'Open Sans', sans-serif; font-size: 15px; background-color: #ffffff;">Robotti was in his early 30s and had already distinguished himself among the hard-charging young prosecutors of the Eastern District. He was smart, organized and a glutton for long hours. Colleagues affectionately nicknamed him the Robot, but they saw him as more than just a grind. After joining the international narcotics unit in early 2015, he was assigned a stack of Sinaloa files, including Guzm&aacute;n&rsquo;s. But after Guzm&aacute;n was recaptured by an elite team of Mexican Marines, President Enrique Pe&ntilde;a Nieto insisted that the trafficker would be prosecuted in Mexico. Robotti needed other work.</p>
<p class="css-at9mc1 evys1bk0" style="margin: 0px 0px 15px; vertical-align: baseline; color: #777777; font-family: 'Open Sans', sans-serif; font-size: 15px; background-color: #ffffff;">&ldquo;Who&rsquo;s doing your case?&rdquo; he asked Cahill and Beck. &ldquo;I want it.&rdquo;</p>
<p class="css-at9mc1 evys1bk0" style="margin: 0px 0px 15px; vertical-align: baseline; color: #777777; font-family: 'Open Sans', sans-serif; font-size: 15px; background-color: #ffffff;">Investigators would soon begin to see Nayarit as a microcosm of the narcostate that U.S. security officials had long feared Mexico could become. Its telegenic young governor, Roberto Sandoval Casta&ntilde;eda, came to power in 2011 as a standard-bearer of the Institutional Revolutionary Party, or P.R.I. The party, which dominated Mexican politics until 2000, still held Nayarit in a tight grip. Sandoval&rsquo;s campaign promised a return to the stability of the past and an end to the violence that had turned the sleepy state capital, Tepic, into one of the most dangerous cities in the world.</p>
<p class="css-at9mc1 evys1bk0" style="margin: 0px 0px 15px; vertical-align: baseline; color: #777777; font-family: 'Open Sans', sans-serif; font-size: 15px; background-color: #ffffff;">Nayarit was then awash in the bloodshed of the Sinaloa-B.L.O. war. The mangled bodies of combatants, cops and innocent bystanders turned up on street corners and hung from highway overpasses. Sandoval made contact with the Beltr&aacute;n brothers, before securing the P.R.I. nomination, one of the governor&rsquo;s former aides would later tell investigators. They had had a presence in the state for years, but Sandoval, who was then Tepic&rsquo;s mayor, offered to let them operate freely if they helped finance his campaign. They just had to keep their violence to a minimum.</p>