LYNN – A Somerville man was sentenced to 10 to 12 years in prison last week after pleading guilty to manslaughter in the 2004 death of 25-year-old Gary Denton of Lynn, according to the Middlesex County District Attorney’s Office.Manuel Spencer, 24, pleaded guilty Aug. 4 in Woburn Superior Court and was sentenced Sept. 4 by Judge Hiller Zobel.Authorities say Spencer and Kevin Hanover got into an altercation with Denton around 2 a.m. March 15, 2004 outside the former Good Times Emporium in Assembly Square. Spencer appeared to give Denton a hug but when he walked away a knife could be seen protruding out of Denton’s abdomen, authorities said.The suspects were arrested 12 days later by State Police. Spencer was originally charged with first-degree murder and Hanover was charged with being an accessory to murder after the fact.