Kathleen Hilton who has been charged for murder and arson of killing a family of five on the top floor trial has begun Friday in Lawrence Superior Court.

62 year-old, Hilton torched a triple decker at 44-46 High Rock St. in Lynn in February 24, 1999, inadvertently killing a family of five living on the top floor.

According to reports, the defense team lawyer Michael Natola described Hilton as mildly retarded, with having a mental disorder and with an IQ of 71.

She purportedly made threats earlier that she intended to burn down the building where her son's ex-girlfriend, Krystina Sutherland, lived with Hilton's two grandchildren, because the woman would not allow visitation privileges.

She is innocent and why should would never harm her grandchildren, Natola said, she tried to cross a police line at the fire scene to save them.

He also pointed an accusatory finger at Loayza, suggesting there are more reasons to suspect him of arson, including an incident just after Christmas 1998 when he allegedly set fire to a holiday ornament attached to Sutherland's apartment door.

The prosecutor, said records show Loayza was at work at Tech Pak in Peabody when the fatal fire broke out. Forrest Lambert, the first witness among the four over 50 witnesses in the case and a former Tech Pak night supervisor, confirmed as much.

The trial before Judge Howard Whitehead resumes Tuesday when the jury of eight women and seven men will visit key locations in Lynn. More than 105 potential witnesses were notified and about 50 will likely be called to testify, Natola said.

Hilton has spent the past 10 years at the state prison for women in Framingham.