New EnglandKiller gets life without paroleCAMBRIDGE, Mass. (AP) — Anthony J. Jackson has been sentenced to life in prison without parole after being convicted of murdering a Winthrop art teacher.The verdict came yesterday four years to the day after the body of Ruth A. Hamilton, 23, was found in her Cambridge apartment. She had been raped and strangled, police said.Judge Thomas Dwyer also imposed a sentence of 20 to 30 years on Jackson, 27, of the Dorchester section of Boston, for his conviction on charges of rape and robbery.Dwyer stipulated Jackson’s life term would not begin until he has completed his current 15-20 year term for assault with intent to murder two Cambridge policemen.Jackson also was indicted for the 1972 slayings of three other young women, who were among eight women slain between July and December 1972 in a string commonly known as the hitchhike or coed slayings.