Yes, all poisons can be traced. However, putting one in drugs that has been found in them previously gives you an alibi for why you weren’t the poisoner. If someone puts 2CCs of strychnine in the herion that someone is shooting in addition to what they normally do, it could be written off as a drug dealer measuring the wrong amount. Why would the loving wife ever poison her rich hammer-junkie husband?
Or y ou could give them ecstasy that is instead PMA. It is found in fake ecstasy and raises the body’s temperatures to deadly heights. 3 or 4 tabs would prolly kill or maim someone. Great for offing ravers! : )
Of course, if you act the wrong way or get sauced and tell someone, you’re toast.