Thallium poisoning? Now someone in the lab has really lost it. But that seems to be what happened in New Jersey, with a chemist from Bristol-Myers Squibb accused of doing in her husband.
A note to the Newark Star-Ledger and some other newspapers: even though a hot isotope of it is occasionally used in medicine, the thallium in this case was not radioactive. It doesn't have to be; it's a good old-fashioned chemical poison. The element enters cells readily, being taken up as if it were potassium, but once it's there it starts disrupting all kinds of processes by latching on to sulfur atoms. It was good enough for Agatha Christie to use it for one of her plots, which (interestingly) seems to have publicized it enough that several other thallium plots were discovered or foiled because of her novel.
As even Wikipedia points out, thallium was "once an effective murder weapon", but the emphasis is one "once". That time is long past. Forensically, it's not the first thing that you think of, certainly, but it got picked up at autopsy in this New Jersey case. And it's not like there's any other way a person could get a high level of the element in their tissues, nor, with modern analytical techniques, can it be mistaken for anything else. Honestly, anyone who believes that they have a good chance of getting away with a thallium murder is just not thinking the whole business through.
There are no details about how the crime was done, but we can assume that some kind of soluble thallium salt was put into the victim's food. Thallium chloride is the cheapest source (as usual - Primo Levi was right when he said "chlorides are rabble"), but I'm not sure how cost-conscious the accused was. She very likely got the compound from work - and even there, it wouldn't surprise me if she had to order it up on some pretext, which will certainly make the investigation easier. Thallium's not a very common metal in organic chemistry - I've seen some uses for it, but nothing compelling enough to make me want to try it.
It's odorless and tasteless stuff, by all accounts. But it's a stupid poison. I'm not going to speculate on better methods - I haven't put that much thought into the topic, really - but there have to be some, possibly with obscure and nasty natural product toxins. Not that it's so easy to get ahold of those, but the Engineer's Triangle still applies, to murder as to everything else: Good, Fast, Cheap: Pick Any Two.
So in the end, we have what looks like a vindictive (but not very competent) poisoner, a dead victim, and all kinds of trouble and fallout for the innocent bystanders in all the families concerned. A sordid business.