A Cohasset man accused of killing his brother-in-law at a birthday party in May has been cleared of all criminal charges, Norfolk County prosecutors announced today.

John McDonough, 46, was charged with manslaughter and assault and battery after getting into a physical altercation with his brother-in-law, David Hoelzer. Police said Hoelzer, whose birthday it was, had become unruly after consuming too many alcoholic beverages and McDonough put him in a head lock.