For those searching for motive:
An Overview of Filicide
One of the most influential classifications of child murder was created in 1969 by Phillip Resnick. He reviewed 131 cases of filicide committed by both men and women that were discussed in psychiatric literature dating from 1751 to 1967.
He developed five categories to account for the motives driving parents to kill their children:
1. Altruistic filicide—The parent kills the child because it is perceived to be in the best interest of the child.
A. Acts associated with parental suicidal ideation—The parent may believe that the world is too cruel to leave the child behind after his or her death.
B. Acts meant to relieve the suffering of the child—The child has a disability, either real or imagined, that the parent finds intolerable.
2. Acutely psychotic filicide—The parent, responding to psychosis, kills the child with no other rational motive. This category may also include incidents that occur secondary to automatisms related to seizures or activities taking place in a post-ictal state.
3. Unwanted child filicide—The parent kills the child, who is regarded as a hindrance. This category also includes parents who benefit from the death of the child in some way (e.g., inheriting insurance money, marrying a partner who does not want step- children).
4. Accidental filicide—The parent unintentionally kills the child as a result of abuse. This category includes the rarely occurring Munchausen syndrome by proxy.
5. Spouse revenge filicide—The parent kills the child as a means of exacting revenge upon the spouse, perhaps secondary to infidelity or abandonment.
The most common motive in Resnick’s study was altruism. In total, this category accounted for 49 percent of the cases reviewed. The least common motive was spousal revenge, which accounted for only two percent of the murders. This comprehensive classification system can be applied to both female and male perpetrators.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2922347/
