Today I Learned

I agree with chemical_cutthroat that it'd probably be illegal to set one.

https://en.wikipedia.org/wiki/Mantrap_(snare)

Mantraps that use deadly force are illegal in the United States, and in notable tort law cases the trespasser has successfully sued the property owner for damages caused by the mantrap. There is also the possibility that such traps could endanger emergency service personnel such as firefighters who must forcefully enter such buildings during emergencies. As noted in the important American court case of Katko v. Briney, "the law has always placed a higher value upon human safety than upon mere rights of property".[5]

However, I think that there are viable ways that someone could rig it up before their death. Like, specify "use this prepared coffin in this specified way in the event of my death" and don't mention any mantrap.

If the dead person installed it prior to their death, then their estate would be liable. If their estate has already been settled, though, I don't think that there would be any viable recourse for someone who is injured or killed by such a trap.

But if the concern is theft of corpses for sale to medical schools...I don't think that such a shortage exists any more.

searches

This says that it was largely an artifact of a period when people had moral objections to dissection of corpses, so didn't want to donate their corpse, coupled with the rise of medical schools needing corpses. This says that it happened later than I expected, though, with the 1950s to 1970s being a big push for donation.

https://theconversation.com/from-grave-robbing-to-giving-your-own-body-to-science-a-short-history-of-where-medical-schools-get-cadavers-199947

In 1962, Unitarian advocate Ernest Morgan published “A Manual of Simple Burial,” which promoted memorial services as alternatives to lavish funerals. He included a directory of medical schools and dental schools that accepted whole-body donations.

Journalist Jessica Mitford, in her wildly popular 1963 book that condemned the funeral industry, “The American Way of Death,” also endorsed that practice. She helped make giving your body to science a respectable, even noble, alternative to expensive conventional burials.

In the early 1960s, Protestant, Catholic and Reform Jewish leaders also came out in favor of donating bodies to science.

By the late 1960s and early 1970s, some anatomy departments began to organize memorial services to acknowledge donors and provide some closure for their loved ones.

Word of such efforts further encouraged whole-body donation.

Letters of encouragement

We reviewed dozens of unpublished letters to and from donors in the 1950s to the early 1970s, in which anatomy professors encouraged potential whole-body donors to see themselves as heroically giving to medical science. Early donors frequently expressed this altruistic vision, wanting their mortal shells to participate in advancing knowledge.

By the mid-1980s, most medical and dental schools relied on donated bodies to teach anatomy, although a few unclaimed bodies still make their way today to medical schools. Technology has revolutionized anatomy teaching, as with the National Library of Medicine’s Visible Human Project, but cadavers are still needed.