A<unk>  is a type of murder or murder-suicide in which at least one spouse and one or more children are killed.  In some cases all of the family members' lives are taken. 
Of 909 cases of mass murder (defined as 4 victims within a 24 hour period) in the US from 1900 to 2000, more than half occurred within an immediate family. So that although the total number of<unk>  cases are relatively rare, they are the most common form of mass killings. However, statistical data is difficult to establish due to reporting discrepancies.<unk>  differs from mass murder in that the murder kills family members or loved ones rather than anonymous people. This has a different psychodynamic and psychiatric significance, but the distinction is not always made. 
A study of 30 cases in Ohio found that most of the killings were motivated by a parent's desire to stop their children's suffering.
In Australia, a study was done of seven cases of filicide followed by suicide in which marital separation followed by custody and access disputes were identified as an issue.  Some common factors such as marital discord, unhappiness, domestic violence, sexual abuse, threats of harm to self or others were found in varying degrees. It was not clear what could be done in terms of prevention.
Familicide
Vinyl ether
Tienilic acid
Pyritinol
Methyl tert-butyl ether
Gedocarnil
Chlormezanone
Tetrachloroethylene