Early in the morning of June 27, 2016, two Chicago police officers chased a Jeep, often at high speeds, for 12 blocks, until the Jeep crashed into another car, killing both drivers. It turned out that the driver of the Jeep was also a Chicago police officer. More than six months later, the city still has not provided any answers about what happened in this mysterious chase.

NBC 5 Investigates compiled video from city red-light and speed cameras, plus surveillance video, to map the chase from beginning to end. The video of the actual crash is graphic. NBC 5 is showing it with the permission of the victim’s mother, who is desperate for answers about how she lost her daughter in this one horrible moment.

The pursuit begins as Taylor Clark’s black Jeep (far right) heads west from a dead stop. The white police vehicle follows, though its mars lights are off.

Clark’s Jeep continues west, with the police vehicle following – its mars lights still off.

The Jeep and police speed by, with the police car’s mars lights still off.

Police continue to pursue the Jeep with no mars lights. Far into the distance – at the upper right – the police lights appear to go on in the sixth or seventh block of the chase.

The pursuit continues, with police lights still on.

One block before the crash: The police car slows down as the officers see the crash occur up ahead.

Looking east as the crash occurs. The police vehicle slows down; turns off its mars lights; pulls over and parks.

Looking north as the crash occurs. The light turns from green to yellow just as Chequita Adams’ car reaches the intersection.