Do I need a lawyer for applying for US Citizenship if...?

I had a DUI 3 years ago (March 2010) in PA. I refused chemical test. I was charged (but not convicted). Went through probation. Completed ARD. Case was dismissed and the records expunged. I have declared so in my application and I am attaching all documents (arrest report, ARD completion, suspension and reinstatement of driving privileges, order of destruction of records, case expungement order etc) With all this in place, should get a lawyer to: 1. File the the application? 2. Represent me at the interview? Your fair and honest answer will be appreciated.