Cornelius sentenced to just 7 years in prison in special deal after murdering her juvenile girlfriend Mattison in St. Louis Missouri while playing Russian Roulette
Posted: Sun Oct 19, 2025 6:48 pm
- Mary Lashawn Cornelius.jpeg (67.47 KiB) Viewed 28 times
ST. LOUIS, MISSOURI — A woman was sentenced for playing Russian roulette with a teen girl, leading to her being shot and killed earlier this year.
Thursday, Mary Lashawn Cornelius, 19, was sentenced to seven years in prison for first-degree involuntary manslaughter in the death of 16-year-old Mattison Johnson.
The sentence was part of a plea agreement with prosecutors, which in turn dropped the armed criminal action charge.
Prosecutors said Johnson was killed on Jan. 3 in a home on the 1400 block of East Grand Boulevard. Police found Johnson bleeding from a head wound on the living room floor. Cornelius was in the same room.
In court Thursday, Cornelius admitted to playing with the gun and "accidentally" shooting Johnson in the head, saying that the two of them were playing Russian roulette. Johnson's mom, Nicole Pettis, believes the two were dating.
"The judge asked Mary point blank, who put the bullet in the gun, and she said, I don't know," shared Pettis.
Pettis also didn't know the two were playing Russian Roulette in her home.
https://www.ksdk.com/article/news/crime ... 535b7eb28c