The undercover investigators appear to work for Detroit-based City Shield, a private security group, and some of their evidence was used by Michigan prosecutors to charge and jail students, according to a Guardian review of police records, university spending records and video collected in legal discovery. Most charges were later dropped. Public spending records from the U-M board of regents, the school’s governing body, show the university paid at least $800,000 between June 2023 and September 2024 to City Shield’s parent company, Ameri-Shield.

The evidence from the undercover investigators has also been used by the university administration in internal disciplinary hearings. The administration cannot initiate cases against students – only other students or staff can – so it spent $1.5m on two consultants who were hired to initiate internal disciplinary action, according to four attorneys and students who went through the process.

In early August, video captured by Walker and shared with the Guardian shows Walker approaching another person who had been recording him from a car. It turned out to be the same man from the Bangladesh protest. The video shows the man acting as thought he is deaf and mute, pretending to use sign language and speaking in an impeded manner. He then starts speaking in a normal voice, and, in an apparent attempt to insult Walker, suggests Walker is a special educational needs student.

In an email, a spokesperson said the university “does not condone or tolerate any behavior by employees or contractors that demeans individuals or communities, including those with disabilities."

A few minutes later, Walker walks behind the man, overhearing him telling another investigator that Walker had figured out who he was. The investigator, who is white, then starts screaming that Walker, who is black, was attempting to assault him. “He wants my wallet!” the investigator screams. Walker also captured this incident on video and shared it with the Guardian.