Was it just a random attack or did he know the people he killed?
Some interesting FBI stats:
In 2011, in incidents of murder for which the relationships of murder victims and offenders were known, 54.3 percent were killed by someone they knew (acquaintance, neighbor, friend, boyfriend, etc.); 24.8 percent of victims were slain by family members.
Of the female murder victims for whom the relationships to their offenders were known, 36.5 percent were murdered by their husbands or boyfriends.
Of the murders for which the circumstance surrounding the murder was known, 42.9 percent of victims were murdered during arguments (including romantic triangles) in 2011. Felony circumstances (rape, robbery, burglary, etc.) accounted for 23.1 percent of murders.
Serial killings account for no more than 1 percent of all murders committed in the U.S. A serial killer is typically a person who murders three or more people, in two or more separate events over a period of time, for primarily psychological reasons.
