Dallas police say they could conclude their domestic violence investigation of Cleveland Browns quarterback Johnny Manziel by late next week.

Police spokesman Maj. Midge Boyle said Saturday that investigators have reviewed medical records provided by Colleen Crowley, Manziel's ex-girlfriend. Crowley told police Manziel hit her and dragged her into a car in late January.

Manziel hasn't been charged, but a judge has issued Crowley a protection order against him.

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Police haven't interviewed Manziel, but spoke to other several witnesses. Boyle says police want to have their strongest case against Manziel before speaking to him.

A Heisman Trophy winner at Texas A&M, Manziel has had several incidents of trouble in the NFL. The Browns have indicated they will release him next month.