His prints were found all over the apartment, on beakers in a storage shed where the chemicals were kept, and on bomb manuals carried by another man he entered the country with, Ahmad M. Ajaj.
The bomb manuals were discovered when Mr. Ajaj returned from Pakistan in September 1992, six months before the bombing.
The fingerprints of two of the men matched those found on bomb manuals Mr. Ajaj was carrying into this country with Mr. Yousef in 1992, officials said.
The prosecution also suggested that Taraknath Das had used Camille de Berri, to store a bomb manual in her safety deposit box.
To make its case against Mr. Ajaj, the Government will have to prove that he brought the bomb manuals to this country for use in the trade center bombing.
The bomb manual later found its way through V.D. Savarkar to the press at India House for mass printing.
The documents, which were found with bomb manuals and Al Qaeda ammunition inventories, include lists of pseudonyms for international volunteers whom Al Qaeda referred for training in Afghan camps.
A bomb manual published by the Jemaah Islamiah was used in the 2002 Bali terrorist bombing and the 2003 JW Marriott hotel bombing.
Yousef's name didn't even come up until more than a month into the trial, when an INS inspector identified the bomb manuals found in Ajaj's luggage.
Speaking in code by phone on December 29, 1992, Ajaj told Yousef that he had won release of the bomb manuals but warned Yousef that picking them up might jeopardize his "business".