PERRY, Iowa (KCRG) – Dallas County Attorney Jeannine Ritchie released a report Thursday saying no charges will be filed over a fatal school shooting in Perry. The Des Moines Register reports Ritchie said the shooter, who took his own life during the incident, planned and acted alone, and she won’t file criminal charges.

The shooting happened on Jan. 4, when 17-year-old Dylan Butler went to the school armed with a pump-action shotgun and a small-caliber handgun. Butler shot and killed 11-year-old Ahmir Joliff, a sixth grade student at the school, and wounded six others before taking his own life.

The school’s principal, Dan Marburger, was shot while trying to protect students during the attack. He died 10 days later. Investigators, in January, said the evidence indicated Butler worked alone. Ritchie’s report said the evidence doesn’t support charges being filed against anyone at the state level.

The Iowa Department of Public Safety said it is planning to hold a press conference in Des Moines at 10 a.m. Friday to share additional details in the investigation.