Thanks for finding the clip - I thought I was going mad when people were saying this hadn't been said. I think he mis-spoke and should've just ended the sentence with "detectives remain open minded about a potential motive"
I don't think there was anything terrible about him saying that but I don't think he should've said it, I think it was silly, but I think it just boils down to some police being better at communicating to the public than others and its a difficult line to walk with how demanding and aggressive some journalists can be on behalf of a public desire for news and the constant 24/7 news churn.
The other thing is, that I'm quite old school in what I consider 'politically motivated' or 'terror related.' ie I grew up when the IRA were planting bombs all the time and (aside from the fact that paramilitary organisations just end up as thuggery) their political motivations and objectives were clear - they wanted home rule for Ireland.
I find it very hard to understand what Kerry's objective was - if indeed he had one - I would think he's completely unhinged to do what he did, he could've had a lot of amorphous, angry, self righteous thoughts related to Reform policy, social conservatism, Catholicism and so on and so forth. If it was purely Reform - Miss Widdecombe wasn't even a serving MP, she was a 78 year old woman living alone and I just still find that fact so upsetting and disturbing, my mum being a similar age and on her own. Maybe she reminded him of someone he hated? Nobody knows, maybe more will come out when he is in court again and will make his plea, which is October if I recall correctly.