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ARLINGTON (CBS11) – CBS11 has learned an Arlington Police sergeant resigned amid a criminal investigation over the way she investigated child abuse cases.

No word yet what criminal charge the officer is facing.

But Arlington police said she had been promoted to sergeant before the department became aware of allegations of wrong-doing.

The department isn’t naming the officer.

Police spokesperson, Lt. Christopher Cook, said the officer in question was a veteran detective who investigated child abuse cases.

Cook said as soon as the department received allegations the officer closed cases without investigating them, they reviewed all of her related files.

The department said at least one case wasn’t investigated properly.

CBS11 is waiting to hear how many others may have also been mishandled.

The department said its administrative review recently became a criminal investigation.

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