Police made a statement to that effect on Friday when they arrested the first suspect (whom they later released);
BBC - 'At Friday’s press conference in Exeter, Longman said the force did not believe the killing was politically motivated, and after an initial consultation with counter-terrorism officers, had ruled out a terrorist motive.'
Why then involve Counter Terrorism Policing North East in the arrest of the second suspect?
To mention again - I think they are only covering all bases just in case.