They then hid them in the ceiling of a training room.
Investigators found software, pornography and articles about making drugs and explosives on the machines.
The discovery came after IT staff flagged unusual levels of internet activity on a contractor's account.
The PCs were found in 2015 but the case has only just been made public.
A report on the incident has been published by the Ohio Inspector General's Office and forwarded to the Ohio Ethics Commission and local officials.
