Say you’re a Sao Paulo resident aspiring to a zoo serial killer career. You’ve got some poison, sodium fluoroacetate, that you’ve either bought or made yourself. The poison must be ingested to work, yet it can’t be put in the food or water–either you don’t have access to the meal preparation areas or have decided that dosing path is far too obvious. How do you go about your killing spree?
Sodium fluoroacetate can theoretically kill if it’s inhaled, but it’s hard to deliver a lethal dose to the target of choice. Wind patterns and all that, plus you’d probably have to wear a surgical or painter’s mask to cut the risk of inhaling a lethal dose yourself. It might be possible if there’s a job at the zoo that involves wearing a mask as part of its description, but the delivery method is still unsure. Animals are one thing when it comes to investigations, but a wind shift that kills a kid or two would bring an entirely different level of official attention to the case.
So the poison has to be delivered orally. No problem, right? People are always feeding the animals at the zoo. But they do it less now than they used to, and besides, someone might remember another person throwing the tapir a peanut or two on the day that animal died. Getting a job at the zoo lessens that possibility, and given the lack of witness it’s almost certain this is an inside job, but there’s always the chance that the animal won’t eat the poisoned comestible, and hanging around the cage long enough to make sure one way or the other is bound to invite suspicion at a later date.
So what’s left? Ice cubes. Sodium fluoroacetate is soluble in water at 68?F (20?C). Mix it up in tap water, freeze the resultant solution in an ice tray, and carry it to work at the zoo in a sandwich cooler. Lots of people carry something similar to work everyday; it would attract no notice at all. Then, when you’re making your rounds carry a “drink” around with you. Every now and then, leave an ice cube where the animal can get at it. If they eat it–great, another score. If not–no problem, the evidence melts away in a matter of minutes. Anyone who sees the leftover water will dismiss it as a spill, or urine, and not even think to test it. If the police even bother to look in the cup, all they’ll see is ice.
Odds are such an approach would kill more of the curious animals, the ones that like investigating their surroundings, and the monkeys, chimps, elephants, tapirs and dromedaries that have died so far are all species known for their curiosity, as well as an ability to pick up small objects; the primates with their fingers, the elephant with his trunk, the tapir with its proboscis and the dromedaries with their flexible lips–no hippos or oxen on this list.
So, if ice is the delivery method, who is the delivery person? The article assumes that it is someone with a good knowledge of chemistry and biology, presumably because since sodium fluoroacetate is banned in Brazil, the killer is having manufacture his or her own. Said assumption could well be incorrect. Brazil, like most other South and Latin American countries, has a thriving black market, and sodium fluoroacetate, under the name of Compound 1080, is definitely available on the black market, though it is a bit pricey at $1000 per 8-oz can.
Odds are that if the sodium fluoroacetate was bought on the black market, it’s a cheaper, domestically produced version of Compound 1080. Since demand for it is obviously high, the relative ease with which sodium fluoroacetate is manufactured should have produced a cheap alternative soon after the substance was banned. Certainly someone in the poison chain has a knowledge of chemistry and biology, but it need not be the killer.
Who, by the way, is probably a woman, as most poisoners down thru the ages have been. I’m not going to attempt to build a detailed profile, but I’d suspect she is one of the lower-skilled workers at the zoo, perhaps someone detailed to clean out the cages, which would give her all the acceess she needs to the animals. It’s probably that she sees the job as beneath her. She may also resent the relative comfort and luxury the animals live in–Sao Paulo has huge numbers of desperately poor residents, it’s not hard to understand the resentment a member of the lower classes may feel towards animals with better living conditions than she herself has.
She’ll almost certainly kill again. If there’s more than one incident, then they’ll continue until the killer is caught, an event which Sao Paulo should hope comes sooner rather than later. For most serial killers, animals are just a first step.
