On August 13, 2023, 16-year-old Omar Diaz of Highwood was fatally shot while walking on the sidewalk in the 2300 block of Green Bay Road in Highland Park, Illinois. The shooting occurred about 11:30 a.m.; responders found Diaz unresponsive and he was taken to Highland Park Hospital, where he was pronounced dead. The Lake County Coroner’s Office ruled the cause of death a gunshot wound.

Investigators say Diaz and another 16-year-old from Highland Park, Estiven Sarminento, were acquaintances involved in an ongoing dispute. After a brief conversation, Sarminento allegedly pulled out a gun and shot Diaz. Witnesses initially described the shooter as a male in all black and thought he fled on a bicycle, though investigators later determined he likely fled on foot. A friend who was on a Snapchat call and who witnessed the shooting helped police identify Sarminento.

The Lake County Major Crimes Task Force and Highland Park detectives used recovered evidence, interviews, and video surveillance in the investigation. Estiven Sarminento was arrested August 14, 2023, and charged as an adult with two counts of first-degree murder; bond was set at $5 million at his first court appearance on August 15, 2023. Did anyone see Omar that morning or have information about the dispute between him and the other teen?