SALEM – Former Peabody police officer George A. Sideris has been committed to a state mental facility for another year after medical officials determined he is still not competent to stand trial and is a danger.Sideris, 38, charged with assaulting and beating his elderly mother into a coma in 2004, has been held at Taunton State Hospital since last July after being deemed mentally incompetent to stand trial for the attacks on his then 73-year-old elderly mother, Melpomeni Sideris.The last attack on Thanksgiving Day in 2004 occurred inside their Peabody home on Ellsworth Road, which they shared. The home has since been sold.In Salem Superior Court Tuesday afternoon, Assistant District Attorney Karen Hopwood reported to Judge Timothy Q. Feeley that Taunton medical officials were seeking to commit Sideris for another year because he is still considered incompetent to stand trial and is a danger.Sideris had been in custody at Bridgewater State Hospital since April 2008 after he tried to commit suicide in his apartment at 59 Walnut St., Peabody. He then was transferred to Taunton State Hospital.Melpomeni Sideris, 78, passed away last January following a lengthy illness. She had been at a local nursing home. George Sideris was her only survivor.The case has been continued until July of 2011.