Last Friday, a technician at Google was involved in a Google Hangout and dropped a bit of knowledge.
Apparently if a penalised site is redirected to your non-penalised site, the penalty won’t transfer. However, as with all things related to Google, it’s a little more complicated than that.
If you have a penalised site that you own, and you redirect it to another one of the websites you own, it’s likely the penalty will follow you.
If you have an un-penalised domain and some one you don’t know redirects it to your domain, the penalty won’t transfer. This will be classed as negative SEO and Google will pick up on this pretty quickly.
This has long been part of the industry and Google have been catching this for years. Take a look at the video below and see the full conversation: