It has been assumed for months that the prosecution of Joaquín Guzmán Loera, the Mexican drug lord known as El Chapo, would be an undertaking of major proportions.

At the news conference in January when the charges against him were announced, federal prosecutors described a Shakespearean cast of more than 40 witnesses who would testify that, over three decades, Mr. Guzmán had built the world’s biggest drug empire, employing an army of assassins and earning billions of dollars by trafficking his product with a rotating fleet of trucks, planes, fishing boats, submersibles and yachts.

But on Friday, the true scope of the case came into view, and the details suggest it is going to be enormous. At a hearing in Federal District Court in Brooklyn, prosecutors said that Mr. Guzmán’s trial could last three months and include up to 1,500 audio recordings of the defendant and his allies alongside nearly 10,000 pages of documents. The presiding judge, Brian M. Cogan, set what he called an “aspirational” trial date: April 2018.

Image Mr. Guzmán, who is known as El Chapo. Credit... Tomas Bravo/Reuters

The sweeping nature of the case, which will track Mr. Guzmán’s rise from a teenage marijuana farmer to an international kingpin who carried a diamond-encrusted pistol, is matched by his outsize reputation. The United States attorney’s office in Brooklyn has portrayed him not only as the world’s most sophisticated drug dealer, but also as a coldblooded killer who ordered the deaths of thousands of people during Mexico’s brutal drug wars.