Police discovered fragments of a "silent conversation" writing in a document on Dart's laptop and then deleting the text.
Counter-terrorism teams also believe that the pair used the same tactic walking down the street with a mobile phone.
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Critics are ambivalent to this year's slate of winners, who were picked in part by American directors Joel and Ethan Coen.
1.5m European citizens will miss out on the chance to vote on whether Britain stays in or quits the EU.
A quiet night ahead of us weather wise, with a mostly dry day tomorrow.