Chicago police say the body camera of an officer involved in the fatal shooting of an unarmed 18-year-old last week was not recording at the time.

Department spokesman Anthony Guglielmi said Monday an investigation is underway to determine why the equipment didn't capture the shooting of Paul O'Neal of Chicago.  Autopsy results show O'Neal died Thursday of a gunshot wound to the back during a stolen vehicle investigation.

Three officers involved in the shooting were relieved of their police powers after officials said a preliminary determination concluded they violated department policy.

Chicago's use of body and dashboard cameras increased significantly in the wake of the release of a video last fall of a white officer shooting black teen Laquan McDonald 16 times in 2014.

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