Liens: Help

My question involves vehicle registration or title in the state of: Arizona.I bought a car from a private owner,and failed to mention title had a lien on it.the way I found out is when I tried putting the title under my name at DMV they said the lien was for not paying resatution fine the private owner failed to do.Can I pay the resatution fine to the courts without the owner(I understand the owners name is on the title)I'm trying to avoid all that ,would the bill of sale be good enough has proof of purchase?somebody please help me
"Desperately seeking title"

Liens: Help