Diane Downs

Shot her three children.

http://www.crimelibrary.com/fillicide/downs/

Book by Rule, Ann.
SMALL SACRIFICES: A True Story of Passion and Murder. 
NY:New American Library,19871st ed.,5th ptg.487pp. 
VG+ hardback/VG+ DJ 
The crime was truly horrifying: the shooting of 3 small children 
in the seemingly idyllic community of Springfield, Oregon. The 
police searched in vain for the 'shaggy-haired stranger' whom the 
children's mother, Diane Downs, accused - until, finally, a 
realization dawned that was even more horrifying than the crime: 
Diane had shot her own children.Photos.