SHEBOYGAN, WI (WHBL) - The former Random Lake School District employee who had stolen hundreds of computer tablets from the district has been convicted on felony theft charges. 33 year old Mark Ustby of Milwaukee was back in Sheboygan County Court this week and pled no contest to the charges. He remains free on bail with sentencing set for January 3. Ustby had been in charge of the technology in the schools and abruptly resigned on August 28th. A day later, school officials discovered 500 tablets and one laptop missing. Ustby later admitted he had sold the tablets, worth about 180-thousand dollars, on Craigslist. He’s now facing up to 20 years in prison.