The death of the Caneiro family — Keith, Jennifer and their two young children — is at least the ninth mass murder in New Jersey's history and the second in Monmouth County in the past year.
FBI defines mass murders as incidents that involve the homicide of four or more people during one event without a cooling off period, typically in one location.
More frequently, homicides that hit families come as murder-suicides, said Joe Giancolone, an adjunct professor at John Jay College of Criminal Justice and a retired New York Police Department sergeant who was the commanding officer of the Bronx Cold Case Squad. At least six murder-suicides occurred in New Jersey in 2018 alone.
Key for the investigation will be the potential for houses in the affluent Colts Neck neighborhood to have residential video surveillance that investigators can comb for cars and people arriving at the Caneiro home, Giancolone said.
He called potential video surveillance one of the "forensic horsemen" — the other keys being cell phone, internet and financial records — that will help authorities determine a motive in the case.
Meanwhile, the fire at the Willow Brook Road home, while it may have been intended to destroy physical evidence, meant police were called to the crime scene faster than they may have otherwise, he said.
The deaths of the Caneiro family come after the New Year's Eve mass shooting of a Long Branch family. Then 16-year-old Scott Kologi is facing four counts of murder and a weapon charge in the killings of his parents, 42-year-old Steven and 44-year-old Linda Kologi; his 18-year-old sister, Brittany Kologi; and a family friend, 70-year-old Mary Schulz.
Colts Neck fire: Caneiro family deaths marks New Jersey's 9th mass murder