A 15-year-old girl and her 16-year-old boyfriend have been arrested in connection with the killing of five members of her family and the injury of two others in East St. Louis, Illinois, United States.

The teenagers, whose identities have not been released because they have not been formally charged, were arrested after authorities said they were linked to a shooting spree across multiple locations on Sunday, July 12.

Police identified the victims as 24-year-old Devin May, the girl’s cousin; her step-siblings, 21-year-old Quentin Thompson and 25-year-old Shania Thompson; her 74-year-old grandmother, Patricia May; and her 49-year-old aunt, Cherie May.

The girl’s father, Marcus May, said he was devastated by the deaths and revealed that his daughter had shown troubling behaviour before the incident.

According to the St. Louis Post-Dispatch, May said he received a warning from the girl’s mother days before the shooting that their daughter had run away from home and taken her mother’s gun.

He said the teenager had been facing disciplinary issues at school, which led both parents to remove her from school and begin homeschooling her. He claimed the decision upset his daughter, who lived with her mother, and that she had previously run away from home and taken her mother’s credit card.

May also alleged that his former partner had warned him about disturbing conversations in a group chat involving their daughter, her boyfriend and other teenagers, where they reportedly discussed harming family members.

He said the situation worsened after his daughter allegedly stole her mother’s gun shortly before the shooting.

On the day of the killings, May said his mother, Patricia May, contacted her granddaughter and pleaded with her to return home, assuring her that the family would help her through her problems.

May said he also contacted the boyfriend’s parents and asked them to keep their son away from his daughter.

The girl’s mother later reported her missing and informed police that the firearm had been taken, but the family received no updates before the shooting occurred.

May said he woke up on Sunday morning to several missed calls and messages and immediately feared something had happened.

Authorities said the victims were found at different locations in East St. Louis. Shania Thompson was discovered inside a vehicle behind an abandoned property near May’s home, while her brother Quentin was found nearby across Interstate 64.

The remaining three victims were found at the Samuel Gompers apartment complex.

Two other people were also shot during the incident and suffered serious injuries but survived.

Illinois State Police Director Brendan Kelly described the incident as a targeted mass shooting. He confirmed that the two teenagers had been arrested but said they had not yet been formally charged.