1) Classical study 
Senicide or geronticide is the abandonment to death, suicide or killing of the elderly. == History == Societal views and legal repercussions have varied greatly in regards to senicide. Focusing on `old people`, van Hoof in 1990 writes that, of the 960 cases he explores, 87 address the motives of old people to commit suicide. Of these suicides, t.....
killing of old men
the act of killing an elderly person
senicide, senicidal The killing of the old men of a tribe, etc.