SALEM – The son of a Lynnfield man beaten to death by another father during a fight at a hockey rink nearly nine years ago has been sentenced to jail for 18 months.Michael Costin Jr., 20, 18 Parsons Road, was sentenced Tuesday after pleading guilty to beating his girlfriend and stealing her car last Dec. 23.Costin, Jr. is well-known to local authorities after numerous run-ins with the law in recent years.Costin’s father, Michael Costin Sr., 40, died after a fight with 6-1, 270-pound Reading truck driver Thomas Junta on July 5, 2000 over a youth hockey scrimmage that Junta thought was too rough at the Burbank Ice Arena in Reading. Costin Sr. weighed just 156 pounds.The fight was witnessed by about a dozen children, including Costin’s three sons and Junta’s son.Junta was sentenced to 6 to 10 years in prison after he was convicted of involuntary manslaughter in 2002. Junta’s sentence was twice the state’s suggested penalty.Costin Jr.’s lawyer asked for leniency Tuesday, but prosecutors and the judge noted his long list of violations and his failure to live up to the terms of his probation.Costin Jr. was charged with assault and battery with a dangerous weapon and possession of a class D substance in Lynnfield on June 7, 2007 with his younger brother, Sean, being charged with disorderly conduct during the same incident; for multiple motor vehicle violations in Lynn on July 6, 2007 and also on the following day in Nahant for possession of a class D substance, assault and battery with a dangerous weapon, resisting arrest and breaking and entering and for domestic assault and battery and violating a restraining order in Lynn on Aug. 6, 2007.In 2008, Costin Jr. was arrested for trespassing in Salem on Feb. 9 and for numerous motor vehicle charges including using without authority as well as assault and battery with a deadly weapon and four default warrants in Nahant on May 9.According to a published report, the judge said he was sorry about Costin’s father, but it was time to “grow up.”(Material from The Associated Press and Item staff was used in this report.)