William Marton, 63, formerly of the 9500 block of Ohio 60 in Florence Township, was charged with rape and gross sexual imposition in January.
A total of five slash wounds on each side of his neck required 23 stitches. Jail guards distribute small razor blades from time to time for personal hygiene.
After a set was handed out to inmates early Saturday, Marton removed a tiny blade to inflict his wounds inside his cell, deputies said.
After medical treatment and a counseling session, Marton was transported back to the Erie County jail, where he remains on suicide watch.
This entails being checked on every 10 minutes, Erie County Chief Deputy Jared Oliver said.
In January, Marton admitted to touching a juvenile and making her touch him, Oliver said.
The confession came after allegations brought forth by the now-teenaged girl.
She said she was inappropriately touched by Marton from the time she was 7 years old until she was 12, Oliver said.