According to this CNN articleon Ariel Castro, the Cleveland man accused of holding three women captive for close to a decade, Castro is charged with 977 counts – including aggravated murder, on suspicion of ending the pregnancy of one of his alleged captives. It goes on to say…
“Besides two aggravated murder charges, Castro faces 512 counts of kidnapping, 446 counts of rape, seven counts of gross sexual imposition, six counts of felonious assault, three counts of child endangerment and one count of possessing criminal tools.”
Can someone tell me what Ohio thinks is ‘gross sexual imposition’ and how that differs from rape, and what the heck is ‘possessing criminal tools’?
Easily google-able question. 
From the web site of an Ohio lawyer:
"In Ohio, generally, gross sexual imposition (GSI) involves “sexual contact” with another person. Under R.C. 2907.01(B), “sexual contact means any touching of an erogenous zone of another, including without limitation the thigh, genitals, buttock, pubic region, or, if the person is a female, a breast. Such touching must be for the purpose of sexually arousing or gratifying either person.”
Unlike rape, which involves nonconsensual intercourse or oral sex, GSI involves the nonconsensual sexual touching of another person’s erogenous zones."
So, both are nonconsensual sexual contact, but rape consists of intercourse or oral sex, while GSI does not.
Imposition concerns sexual CONTACT, not CONDUCT.
Possession of criminal tools, could be a screwdriver used to pry into a home, as an example.
The link does not say what the “tool” was though?
Here is the Indictment.
When it links, hit; control + f; that will bring up a find box, then key in; tools; it will scroll down to it.
http://prosecutor.cuyahogacounty.us/pdf/2013_07_12/Indictment-575419-13-CR.pdf