LAWRENCE – Opening statements in the case of a Lynn grandmother charged with murder and arson are expected to begin today in Lawrence Superior Court.The last of 15 jurors was impa-neled Thursday in the trial of Kathleen Hilton, 62, of Lynn, who has been imprisoned since shortly after confessing to the 1999 fire that killed a family of five.Authorities have alleged that Hilton torched the triple-decker on High Rock Street in Lynn in an attempt to harm occupant Krystina Sutherland, her son’s ex-girlfriend and mother of their two children. Sutherland purportedly would not allow Hilton’s son visitation privileges. She escaped the fire unscathed, but the family on the top floor, a father, mother, two daughters and a niece, all died from smoke inhalation.During the investigation, Hilton admitted she doused a staircase with flammable scented oil and lit it with a cigarette. Her attorney, Michael Natola, has been attempting to suppress that confession.The case will be heard before Judge Howard Whitehead.