Sergio Paez arrived at the Holyoke, Mass., school district in a time of turmoil, and allegations of abuse against special education students have interrupted negotiations to make him the next superintendent of the Minneapolis schools. Here's a timeline of his tenure and the challenges at Holyoke.

•June 2013: Paez hired as Holyoke superintendent. The underperforming district already was being monitored by the state, which has assumed control of the two worst schools.

•Fall 2013: After the state required Holyoke to integrate disabled students, the district created a therapeutic intervention program at Peck School. Within months, the district received complaints about students locked in closets and hurt by physical restraints.

•Aug./Sept. 2013: The Massachusetts Department of Children and Families began investigating incidents at Peck School. The department conducted four investigations throughout the school year and found evidence of physical abuse involving restraints of children.

•Early 2015: Paez met with parents who showed him pictures of their child's bruised arm. He said he asked staff to investigate.

•March 6: A former staff member, Liza Hirsh, sent Paez a letter saying staff improperly used restraints, secluded students in closets and were not properly tracking suspensions.

•March 20: Paez sent Hirsh a letter saying he took the allegations seriously and intended to investigate.

•April 28: The state board of education voted to take control of the Holyoke district, removing Paez as superintendent.

•April 30: The Disability Law Center sent a letter to the district saying it would investigate the Peck School allegations.

•Dec. 7: The Minneapolis school board named Paez the finalist for superintendent.

•Dec. 9: The Disability Law Center released results of its investigation, alleging staff at Peck slapped students and improperly restrained them.

•Dec. 14: Anthony Gulluni, the Hampden County district attorney, launched a criminal investigation.

•Dec. 16: The Minneapolis district suspended contract negotiations with Paez.