Massachusetts police say Google manager Vanessa Marcotte fought fiercely against her attacker last Sunday and must surely have left the man scratched. And, say police, they know it was a man. That may seem like a given for many people but the unspoken suggestion in this assertion is that cops have DNA. In fact, Boston station WCVB is saying that DNA from a known person is being tested. The attack occurred Sunday between 1 and 3 p.m. as Ms. Marcotte was jogging alone near her mother’s home. Worcester District Attorney Joseph Early Jr. asked for the public’s help Thursday identifying a man with scratches, scrapes or bruises known to informants. Victim Vanessa Marcotte was a 27-year-old Google account manager. She was found dead Sunday night hours after she went for a run near her mother’s home in Princeton, a rural town west of Boston. Police have said they have many tips from the public.