Do we have to commit sins because of another's karma

I have a big question since my childhood and everyone I asked, failed to answer. Please help me. Imagine that there are three men A, B and C. A kills B and commit a sin in a previous bhava. Now A have the karma and C kills A in the next bhawa as a result of A's Karma. My question is, does C make a new karma because of A's Karma. Sorry for my bad english. Have a good day ahead.