Murder-Suicide

Murder–Suicide (aka Homicide-Suicide) is an act in which an individual kills one or more people in addition to killing oneself.

The combination of murder and suicide is usually linked to one of two factors:

Premeditation (The killer intended to murder their victim and then kill themselves.)
Result of emotional guilt and an intense feeling of remorse (Most murder-suicide cases occur between lovers and family members, as it is rare for a Serial Killer or Murderer to kill their victims and then "off themselves.")

Types include:

Suicide-murder, such as suicide bombing or driving a car with passenger(s) over a precipice
Suicide after murder to escape state punishment
Suicide after murder as a form of self-punishment due to guilt;
Suicide after (or before) murder by proxy
Suicide after or during murder inflicted by others
Murder to receive a death sentence willfully
Joint suicide in the form of killing the other with consent, and then killing oneself
Murder before suicide with the intent of preventing future pain and suffering of others

Murder-Suicide Case

Beach House Murder-Suicide Case (wife kills herself after she kills her husband)

Frank Lundy Murder Case (although Christine Hill later kills herself after she killed Frank Lundy, it was mostly due to the rejection of her father)

Separately, the event of "killing oneself to stop another" is a different concept all together. If an individual commits Suicide by approaching the people they intend to kill while putting themselves in considerable danger (either from the intended victims or the method of killing them, such as an explosive), this is not Murder-Suicide. Rather, it's often called "Kamikaze," based on the Japanese fighter pilots in World War II that would crash their planes into the opposing force either as a last ditch effort or as their original plan of assault.