March 15, 1926
Chihuahua City, Mexico
Efren (or Elfren) Loweree kills his wife and sons before taking his own life

According to reports, Loweree told his six sons and wife to pray for their souls before beating them to death with a hammer. Loweree then decapitated the boys with a razor blade and shot himself with a revolver. The reason behind the killings were unknown.

El Paso Herald. March 15, 1926

Other source:
“Un padre deguella a sus seis hijos, hiere a la madre y al fin se mata, El Siglo de Torreon.” March 16, 1926. http://h.elsiglodetorreon.com.mx/Default/Scripting/ArticleWin.asp?From=Archive&Source=Page&Skin=ElSiglo&BaseHref=EDT/1926/03/16&PageLabelPrint=1&EntityId=Ar00109 (Spanish)