On this day, Feb. 4, in 1987, Marybeth Tinning confessed to New York state police to killing three of her children. Tinning is believed to have killed eight of her children in all.

Hers is considered one of the worst cases of Munchausen syndrome by proxy, in which a parent injures a child to gain sympathy from others.

From 1972 to 1985, nine of Tinning's children died. None lived past the age of 4.

After the ninth death, the hospital called state police. Tinning admitted to killing three of her children, telling investigators, "I smothered them with a pillow because I'm not a good mother." She denied killing the others. Authorities suspected Tinning's first child died naturally -- but that she killed the other eight.

Tinning was convicted of murder and is serving 20 years to life in prison.

- Scott McCabe