Cushing Pleads Guilty to Arson and Murder. 

An Old Orchard Beach man charged with killing his mother, stepfather, and brother has pleaded guilty to murder and arson.22-year-old Matthew Cushing previously pled not guilty to three counts of murder, as well as one count of arson.A prosecutor said Cushing acted out of concern that the marriage was breaking up, and that his mother would not be able to support herself.Court documents previously indicated he was angry because his parents declined to fund a backpacking trip in Europe.Cushing admitted to stabbing his mother and stepfather, Carol and Christopher Bolduc, and his 15-year-old half brother, then setting fire to their Old Orchard Beach home in February of 2008.Defense lawyer Joel Vincent says his client wanted to take responsibility his actions.He says there was no formal plea agreement.