A Portsmouth man was found guilty on Tuesday for criminal defamation after he wrote a letter of political nature to city officials and a local paper and signed it using the name of a local Marine. 57 year old Rob McDowell was convicted of a Class B misdemeanor as part of a negotiated plea deal. Charges of unsworn falsification and tampering with a public record were dismissed under a plea deal, while a second count of unsworn falsification was placed on file without a finding for two years. McDowell was arrested in March allegeing that he wrote letters of a political nature and signed them with the name Paul Mahoney. Most of the letters called for budget cuts, while one was an endorsement for School Board member Mary Olea. The letters were mailed over a two-year period and also pushed for the closure of Fire Station 3 and to cut the school, police and fire budgets. Police determined that Paul Mahoney is McDowell's former tenant and a 25-year-old corporal in the Marine Corps did not give McDowell permission to use his name when writing the letters.