Forensic toxicology

The Guardian: UK and Bulgaria Investigate 2015 Poisoning of Bulgarian Arms Dealer

Britain and Bulgaria are jointly investigating the 2015 poisoning of a Bulgarian arms dealer to determine whether it involved novichok, the nerve agent used in the poisoning of Russian double-agent Sergei Skripal and his daughter, Yulia, in Salisbury last year, the Guardian writes. 

Reuters: Old Ties with Russia Weigh on Bulgarian Decision in Spy Poisoning Case

''Bulgaria, which has a strong pro-Russian lobby in government, needs more time to decide whether to follow NATO and EU allies in expelling Russian diplomats over a nerve agent attack on a former Russian spy'', its deputy prime minister said on Thursday, Reuters reported.