TEANECK, N.J. (AP) — Investigators have yet to determine what caused a single-car crash that killed a police officer in northern New Jersey.

Officer John Abraham’s patrol car slammed into a utility pole across the street from Teaneck police headquarters early in the morning on Oct. 25.

The 37-year-old was working a double shift.

Investigators have ruled out mechanical failure.

Police said Abraham’s computer revealed that he had run a license plate number shortly before he crashed. But the out-of-state plate was not on file and Police Chief Robert Wilson says Abraham might have mistyped the number.

An assistant prosecutor told The Record newspaper it’s still not clear when the plate number was entered.

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