Marjorie DiehlArmstrong February 26 1949 April 4 2017 had a history of suffering from multiple mental illnesses including bipolar disorder since her early teens and seems to have been a serial killer Before her mental health deteriorated in her twenties DiehlArmstrong was an exemplary student in high school and earned a masters degree from Gannon College In 1984 she shot her boyfriend Robert Thomas six times as he lay on the couch but was acquitted on claims of selfdefense Her husband and several other partners also died under suspicious circumstances DiehlArmstrong died from breast cancer in prison on April 4 2017 at the age of 68