The former owner of Angela’s Coal-Fired Pizza in Tyngsborough has been released from prison after serving two years on assault charges. Eric Sideri, 51, was convicted in February 2012 for allegedly beating his assistant manager, Lucio Oliveira, with a baseball bat in 2009 and was sentenced to four to five years in prison. The altercation stemmed from Sideri’s suspicion that Oliveira had stolen $21,000 from the restaurant; police say there was no evidence of the theft. This January, the state appeals court overturned the most serious conviction of assault and battery with a dangerous weapon, enabling Sideri to accept a plea deal of two years in prison, deemed served. In addition, he will be on probation for three years and will take a mandatory anger management class.