Military forces work on a van in Winterslow, England, Monday, March 12, 2018, following the nerve-agent attack on Sergei Skripal and his daughter Yuli

Military forces working on a van in Winterslow, England, as investigations continue into the nerve-agent poisoning of Sergei Skripal and his daughter Yulia, in Salisbury, England, on Sunday March 4, 2018. (AP Photo)

Military forces work on a van in Winterslow, England, Monday, March 12, 2018, as investigations continue into the nerve-agent poisoning of Sergei Skripal and his daughter Yulia, in Salisbury, England, on Sunday March 4, 2018. (AP Photo)