In the first place, there was no "Inquisition", there were many inquisitions.

It was common for people to petition to move their case from the state courts to the courts of the inquisitions because they were fairer.

A good book on the topic would be Rodney Stark's "Bearing False Witness: Debunking Centuries of Anti-Catholic History". He is a sociologist of religion.

He writes “The standard account of the Spanish Inquisition is mostly a pack of lies, invented and spread by English and Dutch propagandists in the sixteenth century during their wars with Spain, and repeated ever after by the malicious or misled historians.”

He does a splendid job of dismantling the "Hilter's Pope" and associated slurs, which today alone on this very blog I have read repeated by self-described Catholics.