What are your thoughts on the UK expelling 23 Russian diplomats and taking other measures against Russia over the poisoning of a British spy and his daughter in London?

So a British spy and his daughter were poisoned in London. Investigators think the poison was a nerve agent made in Russia, but have not captured any suspects or identified a motive. The spy had been convicted in Russia of passing information to MI6 but was returned to England in a spy swap. Russia denies any involvement in the incident and has offered to co-operate. .... ... ... .... ... ... .... ... ... ... ... ... .. ... ... In response, British Prime Minister Theresa May has expelled 23 Russian Diplomats, calling them undeclared intelligence officers, frozen Russian assets, and suspended high level contact with the Russian government. . .. .. ... . .. . .. .. .. .. .Is this a reasonable response? Could it have been some other group trying to make it look like Russia did it, to drive a wedge between England and Russia? If so, their plan has worked brilliantly. Or is Russia really so diplomatically clumsy that they'd use chemical weapons to kill someone in England who they could have easily killed when he was in their custody? I don't know, frankly I think the whole thing stinks.