CHICAGO (AP) — A gunman targeting someone else on Chicago’s southwest side instead shot an 8-year-old girl in the head, killing her, police said.

The Cook County medical examiner’s office identified the victim Sunday as Melissa Ortega, whose family recently moved to Chicago from Mexico. Police said she was walking on the street with her guardian on Saturday afternoon when someone fired shots at a 26-year-old man who was leaving a nearby store. Police believe he was the intended target.

The girl, who was shot in the head, was pronounced dead at a hospital. The man police believe was the intended target was shot in the back and was hospitalized in critical condition. Authorities did not have an update on his condition Sunday.

The attacker got away and had not been arrested as of Sunday.

Police Superintendent David Brown said the department “will not rest until the perpetrators” are brought to justice.

“The tragic and senseless murder of 8-year-old Melissa has shaken our city,” he tweeted Sunday. “There are no words of comfort when a child’s life is cut short. There are no words that can describe the grief of a family.”

The shooting happened amid a spike in homicides in Chicago. Last year was the city’s deadliest in a quarter century, with roughly 800 homicides.

Melissa was a student at Emiliano Zapata Academy, an elementary school in the city’s heavily Mexican Little Village neighborhood, according to the Chicago Teachers Union.

Her family emigrated to Chicago from Mexico last year, according to family members organizing an online effort to pay for funeral services expected to be held in Mexico.