Transcript for Novichok expert weighs in on poison that sickened UK couple

So hopefully if it's some of the the early announcements that we've seen in the media about. They perhaps some kind of backed the substance of it perhaps for the syringe. While those a man. Massive droves of evidence so it may well be that we can price. That syringe that bag whatever it may well be to manufacture. From them and expect that we can perhaps find out who shipped him. So these and then of course as conventional. DNA and so the fingerprint evidence that may well man stopped provided the police with a kind pleas that they want. And it may well even that these so that sought to give ideas about it how Weathers and expect. We're still talking about a mining cement of agent that is being brought into the UK and this is the remnants of it and yet it's yet to find that. How big that remnant was four these individuals. How much it might have been this proposal that will be able to save it any. Sort of firm decision on on how long enough talk will remain the local. So again if it's inside if its mix within within days back over the history and and certainly going to be at the last blow many months thanks in many years the reason that he would have it in the binary Coleman is to be it is extended shelf life and death. But if you're in a sort of sealed container once it's been makes him will eventually. Start to deteriorate but within months that's unlucky having me. If for example they poured into the grand and as we've had. Very dry weather here. And so route into the dispenser but the hands on the ground mean that that then. Presents a significant threat because it so drugs could see it's up to him come out in the atmosphere. But again these rules all information we should be him from the law enforcement and some of the public helping them virtual.

This transcript has been automatically generated and may not be 100% accurate.