A Declaration Deploring Disestablished, Drunken Detectives

[Spy_Guy]

However, it would be fantastic if there were a way to see the what last chemical substance in a dead body was.

Last I checked, chems don't deplete in dead bodies, so a reagent scanner is all you need for that.

Sometimes they deplete in the body and then the victim dies, like with 5 unit poisons like kuru and the many forms of initro.

I dunno about initro, sometimes they'll kill you dead before depleting. I used to abscond with the body to draw the remainder out with a syringe when I used it.
Remember to recycle, folks.