A woman and child were killed and two other minors were injured in an attack in Springfield, police said.
Police Lt. Robert Byrne said a suspect was arrested shortly after officers were called to the home in West Springfield.
Byrne said the officers went to the house after being notified of an ongoing assault. He said that two girls, ages 7 and 14, walked out of the house and told the officers that there were other people inside.
Law enforcement officers entered the house and found the woman and juvenile dead.
The victims sustained wounds consistent with being stabbed.
One child who escapes is treated for life-threatening injuries while the other suffers from severe but not life-threatening injuries.
Witnesses told the police that a man carrying a knife was seen running away from the house. Byrne said officers managed to arrest the suspect a few blocks from the house.
The relationship of the suspect to the victims is unknown, and the police are also working to determine the motive for the attacks.