A Justice Department spokesperson confirmed only that Brown had retired, without providing a reason for his departure.

FBI agent Tracee Mergen resigned after an attempt to investigate the U.S. Immigration and Custom Enforcement (ICE) officer involved in the fatal shooting of Renee Nicole Good in Minneapolis earlier this month, The New York Times reports.

Tracee Mergen, whose FBI squad was involved in the Renee Good investigation and probes into public benefits fraud in Minnesota, resigned last week, sources said.

Records The Times-Picayune obtained show NOPD internal affairs investigators began scrutinizing the senior officer based on a complaint alleging public payroll fraud and “secondary employment” violations.

US District Judge Margaret Garnett ruled Friday that prosecutors cannot pursue a murder charge that could have led to the death penalty if he were found guilty.