I have lived in jurisdictions where folding knives over a certain length were illegal to carry concealed (folding hunter style Buck knives needed to be carried in a sheath that was at least somewhat visible). Likewise Gray had an extensive arrest history. It is quite possible that he was on probation.
As such, some of the terms to his probation could have been:
- You are subject to arrest if you violate any of the adminstrative terms of your probation. Attempting to evade the police could well be an administrative violation of his probation. In addition, he could have failed to identify himself (running could be considered failure to ID?)