Alan Williams resigned as Chicago Bears defensive coordinator last week in part because of inappropriate activity, sources told ESPN's Adam Schefter.
Williams was not involved in any criminal activity, sources told Schefter, but the Bears' human resources department was part of the process that culminated in his abrupt resignation Wednesday.
A digital forensic search was conducted as part of Williams' resignation, according to sources, who added that such a process was part of the team's standard operating procedure.
Williams, 53, announced that he was "taking a step back to take care of my health and family." Both the Bears and Williams' lawyer said a report in Chicago of police activity at the team facility was inaccurate.
Bears coach Matt Eberflus will continue to call defensive plays in place of Williams, who missed last Sunday's game against the Tampa Bay Buccaneers because of an undisclosed personal reason.
The Bears (0-2) visit the defending Super Bowl champion Kansas City Chiefs on Sunday.