Police went in and out of #Skripal door for 3 weeks, before they found the “nerve agent” - at the door.
BUT
The handbook’s authors (on nerve agent), doctors Ian Greaves and Paul Hunt, said Novichok agents act quickly, with their effects usually taking hold within 30 seconds to two minutes of contact.
www.ft.com/content/ea4d1700-2619-11e8-b27e-cc62a39d57a0