Only by gov’t-licensed necromancers, otherwise there’s a risk of witness tampering.

Somewhere in Tokyo there’s a manga author furiously taking notes on this as the plot line. Three months from now a new manga will hit store shelves:

“I got killed and now I’m the key witness at my own murder trial”

That goes to the weight, not the admissibility.

Testimony comes in, jury decides if it’s credible.