LAWRENCE, Mass. (AP) – Police arrested a man Saturday on charges that he beat a 34-year-old mother to death in front of her two sons in the first homicide in this city in almost 20 months.

Officers found Maria Sastre, 34, with severe head injuries in her home early Saturday morning after her sons called for help from a neighbor’s house. Sastre’s 15-year-old also suffered head injuries during the attack but is expected to survive.

Paramedics rushed Sastre to a local hospital, where she died at about 8:30 a.m.

Police arrested Levi Omar Alcantara, 30, just before 8 a.m. near Sastre’s home. Alcantara knew Sastre and her two sons, police said, but officers declined to describe their relationship.

Alcantara, of Methuen, is being held in the Middleton Jail. He is scheduled to be arraigned Monday in Lawrence District Court on charges of murder, assault with attempt to murder and assault with a dangerous weapon.

Police did not specify what type of weapon was used in the attack. Sastre’s 12-year-old son was present but not injured during the assault, police said.

The last homicide in Lawrence was on Aug. 26, 2004. Rafael Castro, 36, was shot in the head in his apartment by a man looking for drugs, police said. A 20-year-old man has been indicted on a first-degree murder charge in the killing.

Lawrence, an old mill town about 28 miles north of Boston, is one of the state’s poorest cities. It has long been plagued by gangs, drugs and violence.

Officials credited community policing and focusing on the three driving forces behind most killings in the city – drugs, gangs and domestic violence – for what had been a 20-month run without a murder.

The last time the city of 72,000 went even a year without a homicide was in 1972.

-Associated Press