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.
More top news
Ann Myatt, who is contesting Jo Cox's former seat, told a hustings: "We've not yet shot anybody so that's wonderful."
The 26-year-old said she was moving on to the "next big chapter" - which includes a new show about her venture into motherhood.
Patchy rain will affect many northern areas of the UK over the next 24 hours.