Contacting DMVs to get owner information is tricky as there is now a Federal Law protecting people from being located. This came about as a result of the Sharon Tate murder back in the 80s.
When you contact the DMV , you want to obtain a title history and let them know you are doing "research." Many states do allow for this.
That failing, if you can afford it, hire a private investigator. DMVs do allow investigators, law enforcement and insurance companies to obtain owner information.