Jesse Pomeroy was the youngest person to be found guilty of first-degree murder in Massachusetts history in 1874. Even though he was just 14 years old, the brutal and violent atrocities he committed led to life in prison, where he died in 1932.

Source Materials:

https://www.aetv.com/real-crime/jesse-pomeroy

https://www.cbsnews.com/news/the-story-of-jesse-pomeroy-14-year-old-serial-killer/

https://allthatsinteresting.com/jesse-pomeroy

https://www.historicmysteries.com/jesse-pomeroy/