TOLEDO, Ohio (AP) — A convicted school shooter and two other Ohio inmates managed to get inside a maintenance access area and spent several months building a makeshift a ladder that they used to escape in September, according to a report released by the state on Friday.

The inmates climbed the ladder to get on the roof of the prison’s administration building and then jumped about 15 feet to freedom. All three were caught within hours of the escape.

The Department of Rehabilitation and Correction’s investigation also found a security camera at the unit where the escape happened wasn’t working because of an earlier lightning strike and that some lighting near the prison needed to be repaired.

T.J. Lane, 20, was serving a life sentence for opening fire and killing three students in a cafeteria at Chardon High School near Cleveland in 2012. 

Lane, who wore a T-shirt with the word “killer” scrawled on it at his sentencing last year, was captured in a wooded area about six hours after the prison break on Sept. 11.

Another inmate was found within minutes just outside the Allen-Oakwood Correctional Institution in Lima while the other was discovered hiding under a boat across the road nine hours after the escape.

A video released Friday by the corrections department showed all three running through a soybean field just outside the prison fence.

The maintenance access area the inmates got into was described in the report as being similar to a crawl space. The inmates were able to open a padlock on a door to the maintenance area, the report said. 

The prison department has since repaired lighting at the prison, updated the alarm system and added razor ribbon on top of the administration building and other areas, the report said.

The state also has reassigned the warden at the prison and demoted the deputy warden.