Police have located a man who investigators say was the subject of a search along Route 3 in Merrimack. The Attorney General’s office said a ‘potential witness’ was the focus as part of the investigation into the shooting death of a homeless woman in Concord last week. Investigators said the search was linked to the death of 37-year-old Jillian Collins who was found dead with a gunshot wound Friday near a tent site in Concord off of Manchester Street. Investigators have not released the man’s identity but emphasize that the man is not a suspect in the case at this time.