Further to my previous response to this post, before anyone corrects me on this:

A 'perpetrator' would be one who carries out the act - could be once or more.

A 'perpetuator' would be one who carries out the act on an on-going basis, the vehice through which the act continues.

That would be the difference in the use of these two words.

If someone wants to clarify this further for me, please do.

Have a good day all!