The witnesses also accused the crime lord of paying off almost every level of the Mexican police, military and political establishment, including an alleged $100 million bribe to one of the country’s former presidents, Enrique Peña Nieto. Mr. Guzmán was said to have ordered the deaths of dozens of his rivals, enemies and informants, and to have armed himself with a gold-plated AK-47, a camouflage patterned M-16 and at least three diamond-encrusted pistols, one with his initials on the handle. Witnesses said he personally killed at least three people, ordering his men to bury one of them alive and to dispose of the other two bodies in a bonfire.

Beyond helping prosecutors substantiate the 11 counts in Mr. Guzmán’s indictment, witnesses painted a complicated portrait of the man himself. They told jurors how he rose from being a poor campesino in the village of La Tuna in the Sierra Madre mountains to become a billionaire narco lord with a $10 million beach house, a fleet of private jets, a yacht he named for himself and a personal zoo. By the end of the government’s case, jurors had heard stories about Mr. Guzmán’s temper, grace under pressure, bottomless libido, workaholic nature, love of the limelight and obsession with spying on everyone around him. They learned about his failed vanity movie project and even got to see a video of his underwear drawer.

Prosecutors were able to assemble all of this because many have been working on the Guzmán case for a decade or more. Well before the kingpin was extradited from Mexico two years ago to stand trial in New York, he was already facing six separate indictments filed in six separate federal judicial districts.

As one of the world’s biggest drug traffickers, Mr. Guzmán presented a unique target. And, with some notable exceptions, building one of the world’s biggest drug trafficking cases against him required a unique level of collaboration. The charges brought against the crime lord drew upon the work of the F.B.I., the D.E.A., Homeland Security, the Narcotics and Dangerous Drug Section of the Justice Department, and United States attorney’s offices in Chicago, Miami, San Diego, El Paso and New York.

When Adam Fels, a prosecutor from Miami, gave the government’s opening statement on Nov. 13, he made it sound as if a single, seamless case had been brought against Mr. Guzmán. But once the government rested, it was clear that there was never only one case against the kingpin, but rather there were several sewn together in a kind of patchwork quilt.

This collage of a case was ultimately tried in Brooklyn on the orders of Loretta Lynch, the former United States attorney general who had previously served as Brooklyn’s top federal prosecutor. It was so extensive that testimony from any one individual witness might have been enough to convict Mr. Guzmán. The amount of testimony was so excessive that Judge Cogan cautioned prosecutors more than once from engaging in overkill.