A pattern of “inappropriate behavior with alumni,” which included hand-holding and “an instance of slow-dancing,” ultimately led to founder Michael Milkie’s resignation, according to a letter sent by a Noble administrator to staff on Tuesday night.

Constance Jones, the president of the Noble Network of Charter Schools, said in the letter that she and Head of Schools Ellen Metz became aware of the inappropriate behavior in October and “immediately voiced a lack of confidence” in Milkie’s leadership. “When confronted with this information and our lack of confidence in Mike, he chose to retire. I want to emphasize that at no point did Noble leadership have knowledge of allegations that required mandated reporting, or that were criminal in nature.”

Asked for comment, Noble administrators referred back to Jones’ statement.

The charter network’s board of directors, led by Allan Muchin, has hired an outside law firm to conduct a full investigation of Milkie’s conduct and review internal procedures for handling complaints. Muchin announced last week that Milkie would retire at the end of the calendar year for “personal reasons” but didn’t describe the exact circumstances behind the sudden departure. 

Jones said in Tuesday’s letter that the board still was reviewing the matter, but the administration decided to communicate with staff because “some circumstances” surrounding the departure would be reported in the news. WBEZ reported that a former Noble principal said that female students told a teacher that Milkie made them feel uncomfortable.

In a statement to WBEZ, the Noble founder acknowledged that he “acted inappropriately toward adult women affiliated with Noble.”

Noble Network is the district’s largest charter operator, with 12,000 students, 17 high schools, and one middle school.

In the conclusion of her letter, Jones asked that staff “continue to come to work with the passion, dedication, and commitment to families that define what it means to be Noble.”

Milkie and his wife, Tonya, were former Chicago Public Schools teachers who opened their first charter campus in 1999 in the city’s West Town neighborhood. They began expanding in 2006 and were buoyed by the Renaissance 2010 plan spearheaded by Mayor Richard M. Daley and his schools chief Arne Duncan that seeded many new charters.

Educators at Noble have been trying to unionize since 2017, a move publicly opposed by Milkie.

Milkie’s resignation comes nearly six months after a Chicago Tribune series revealed systemic lapses in Chicago Public Schools to properly address complaints of student sexual abuse. In response, the district implemented several measures including conducting new background checks for school staff, removing the principals of two schools, and creating a new Title IX office.

This story was updated to reflect that Michael Milkie acknowledged his behavior in a statement to WBEZ and that Noble administrators referred to the letter to staff when asked for comment.