On January 3, 2025, 16-year-old Mattison “Matty” Johnson was fatally shot in her home on the 1400 block of East Grand Boulevard in the College Hill neighborhood of St. Louis, Missouri. The incident occurred around 1:37 p.m., and responding officers found Mattison deceased at the scene. An 18-year-old female, Mary Cornelius, who was present during the shooting and known to the victim, was interviewed by police. Cornelius admitted to holding the firearm when it discharged. She was subsequently charged with first-degree involuntary manslaughter and armed criminal action.
Authorities initially described the shooting as accidental, citing witness accounts that Cornelius had been negligently handling the firearm prior to its discharge. However, Mattison's mother, Nichole Pettis, disputes this characterization, asserting that her daughter was in an abusive relationship with Cornelius. Pettis revealed that her younger daughters, aged 9 and 11, were present during the incident and reported that the two older girls had been arguing throughout the morning. She also stated that Cornelius had been playing with the gun all day and had been asked multiple times to put it away. Pettis believes the shooting was not accidental and is seeking justice for her daughter.
Mattison was remembered as a bright and ambitious teenager who aspired to become a nurse. She had recently returned to school and started working at a local laundromat. Her family described her as the life of the party, known for her pranks and ability to uplift those around her. In the wake of her death, a memorial service was held, and a GoFundMe campaign was established to assist with funeral expenses and support the family's pursuit of justice.
The case has drawn attention to issues of domestic violence among teenagers and the importance of recognizing warning signs in relationships. Pettis has expressed a desire to raise awareness and prevent similar tragedies from occurring in the future. She continues to advocate for her daughter, emphasizing the need for accountability and change.
