Here's the accident report: https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR2002.pdf

Probable Cause: The NTSB determines that the probable cause of this accident was the inappropriate response by the first officer as the pilot flying to an inadvertent activation of the go-around mode, which led to his spatial disorientation and nose-down control inputs that placed the airplane in a steep descent from which the crew did not recover. Contributing to the accident was the captain’s failure to adequately monitor the airplane’s flightpath and assume positive control of the airplane to effectively intervene. Also contributing were systemic deficiencies in the aviation industry’s selection and performance measurement practices, which failed to address the first officer’s aptitude-related deficiencies and maladaptive stress response. Also contributing to the accident was the Federal Aviation Administration’s failure to implement the pilot records database in a sufficiently robust and timely manner.