Police on Sunday night were questioning a man about the throat-slashing attack on a little boy and his sister that morning in Camden, New Jersey. Two other children in the home were not hurt.

Update: Boy Dies Fighting Off Sister's Attacker

The little boy, 6, died from his injuries.

His 12-year-old sister is in critical condition.

The children were asleep when they were attacked early Sunday morning at their home on the 900 block of Ware Street just after 2 a.m.

The girl went door-to-door on her block to get help and finally reached the home of Nakyta McCray, who called 911. McCray said the girl "was barely breathing'' and bleeding profusely when emergency personnel arrived.

The children's father lives out of state, authorities said, and their mother was in the hospital at the time. The kids were being cared for by their 14-year-old sister. Another sister, 9, was also home at the time. They were not hurt.

No one on Sunday understood what the motive for the slashes might have been, but police were looking for a man who lives in the area and apparently has lacerations on his hand.

Neighbors told NBC10 the children's mother got into a dispute with the neighbor about two months ago.

Later in the day, the public information officer for the Camden County prosecutor's office told NBC10 that they are not targeting one person and that they do not have any suspects. Several law enforcement agencies joined Camden police in the search for the killer.

McCray said the man she believed police were looking for is well-known around the neighborhood. She said he plays with the local children and seems to be a peaceful person.

"People would never think he would do something like this,'' she said.

The double stabbing comes shortly after another child died a violent death in Camden. On Aug. 22, a 33-year-old city woman allegedly decapitated her 2-year-old toddler and then fatally stabbed herself