Alan David Patton, 59, of Dublin, Ohio, had been accused of collecting urine in a Lewis Center bathroom -- a charge created specifically for him after he was found doing the same thing at a sports park in 2008.
Sheriff's deputy Brian Blair testified Patton was in the bathroom's only stall when Blair was off duty and entered the bathroom Oct. 29 with his 3-year-old son.
Patton left and Blair found the toilet filled with seat liners and toilet paper, unable to flush, he testified.
Patton returned to the stall after Blair left with his son. Blair then went back into the bathroom and heard paper rustling in Patton's stall.
Blair left and then went in a third time, this time finding the toilet cleaned out and flushing properly. The room smelled strongly of urine, he testified, and Patton was carrying a paper Burger King bag.
Blair wrote down Patton's license plate number as Patton drove away. Patton was arrested Nov. 5.
Patton's attorney, Christopher Soon, called the case "laughable" and presented no witnesses, The Columbus Dispatch reported.
Delaware Municipal Judge David P. Sunderman did not yet schedule a sentencing hearing.
Patton was convicted in 2008 of attempting to collect urine from toilets at Dublin's SportsOhio sports park. But authorities were frustrated at the time because he could only be convicted of criminal mischief and was sentenced to the maximum 60 days in jail.
State lawmakers later passed a law making it a first-degree misdemeanor, carrying a six-month maximum term, to collect any bodily substances without consent and for non-medical purposes.
Patton spent 4 1/2 years in prison after fondling a young boy while trying to collect urine at Columbus's Magic Mountain Fun Centers in 1993.