I googled "matricide" and found this interesting article:
http://www.psychologytoday.com/blog/the-human-equation/201207/matricide-teen-girls
"While severely abused girls who kill rarely show an escalating history of violence towards their mothers, abusive girls do. These girls often have a history of behavior (lying, stealing, truancy) that routinely places them in conflict with parents. This is often, in part, due to inadequate and/or absent limit setting by
parents combined with a history of failed and rebuked efforts at discipline by children. In these cases, the cycle of family violence and conflict often begins with relatively innocuous family discord and increases in frequency and severity as the parents inability or unwillingness to impose meaningful discipline
undermines informal family controls and acceptable codes of conduct. In addition, these parents often go to great lengths to protect their abusive children from formal legal responses to their abusive behavior by not reporting and thereby keeping their abuse hiddensometimes until it's too late."