The teens saw others help Guerrero out of the driver's seat and lay him on the ground before trying CPR. One of the teens said he was traumatized by the sight of the stranger dying on the street. His friend, Haley Thomas, said she felt the same way. "For the rest of my life," said Thomas, 18.
Guerrero was taken to Northwestern Memorial Hospital and pronounced dead. No arrests have been reported by police.
Responding officers initially set up a small crime scene with red tape, later adding a buffer zone in yellow and eventually closing off a stretch of Wacker between Columbus Drive and Lake Shore Drive.
A man wearing orange sweatpants paced inside the scene, talking loudly into his phone about the shooting, while a woman in a denim jacket stood still, speaking only when police asked her questions. "They just rolled up," the man in orange said into the phone. "Started saying things ... "
An officer, on his own phone, covered the mouthpiece and called out to the pair about the shooter. "Where was he sitting at?" the officer asked. "The passenger or driver's side?"
"Passenger," the woman said.
Several cars heading east, in the turn lane to go south onto Lake Shore, slowed or stopped as they approached the scene. Officers flashed bright lights in their direction. "Let's go," an officer yelled. "Move!" A white car with a yellow tree air freshener dangling from the rearview mirror pulled over next to the scene. The officer held his light on the car. "Move!" he repeated and the car drove away.
Across the crime scene, the off-duty sergeant had been talking to police, then walked away to stand near two other men several yards away. One wore a white T-shirt and had streaks of red blood from his nose that had started to dry.
Minutes later, the off-duty sergeant walked back toward the crime tape. He exchanged a few words with the officers, who told him not to come inside the scene. "Stay over there," they warned. "Stay on the other side."
But the sergeant bolted under the tape and into the scene. Officers intercepted him and he continued to argue with them.