BOSTON – A former machine shop manager at Massachusetts General Hospital (MGH) began a state prison sentence on Wednesday in connection with stealing more than $640,000 from the hospital in three separate schemes, Attorney General Martha Coakley’s Office announced Thursday.On Oct. 22 in Suffolk Superior Court, Leonard Wasileski, 66, of Peabody, pleaded guilty to charges of larceny over $250 (three counts). After the plea was entered, Superior Court Judge Carol S. Ball sentenced Wasileski to a term of 12-18 months in state prison, with 10 years of probation to serve upon his release. Judge Ball also ordered Wasileski to pay $640,000 in restitution to MGH.In the three separate larceny schemes, Wasileski sold scrap brass after use in radiation and kept the proceeds for himself, ordered hundreds of unauthorized tools and pieces of equipment through MGH for his personal use, and directed payments for MGH invoices to his personal accounts.The AG’s Office began an investigation in August 2013 after investigators from the MGH Special Investigations Unit conducted a preliminary investigation. Further investigation revealed three separate schemes in which Wasileski stole more than $640,000 in total. Wasileski was employed at MGH for nearly 36 years until his termination in 2013, initially as a machinist and then as the manager of the machine shops within MGH’s Department of Radiation Oncology (DRO).The majority of theft, more than $540,000, was scrap brass sold by Wasileski after it was used in radiation therapy treatments at MGH. The Proton Therapy Center at DRO uses a procedure in which brass discs with customized holes are used to focus radiation beams on cancer patients’ tumors while protecting the surrounding tissue. As manager of the DRO machine shops, Wasileski was responsible for purchasing and customizing those brass discs and with arranging the recycling or scrapping of brass after it had been used. Investigation revealed that Wasileski arranged for the scrap brass to be picked up by scrap vendors but kept the proceeds from that scrap for himself.Wasileski also used his authority as shop manager to make purchases using MGH funds to obtain hundreds of tools and items of woodworking equipment for his personal use. The estimated value of the unauthorized goods was approximately $88,000.In a third scheme, Wasileski stole approximately $12,000 in connection with work performed by MGH employees at the MGH machine shop for a University of Rochester professor’s research. According to investigators, Wasileski sent invoices for this work to the University of Rochester directing that payment should be in the form of checks made payable to him personally, and deposited the resulting checks into his personal accounts.