Christina Riggs

There is no doubt that Riggs killed her children Justin Thomas & Shelby Riggs. She gave police an audio-taped confession detailing how she injected Justin with poison, hoping to make his death peaceful, but instead causing him agony. She then smothered both Justin and Shelby and tried to commit suicide.

UPDATE... Christina was executed by lethal injection

http://www.apbnews.com/cjsystem/justicenews/2000/04/30/riggs0430_01.html
http://www.salon.com/mwt/feature/2000/05/04/death/
http://www.geocities.com/trctl11/riggs.html
http://members.tripod.com/~leelah/index188.html