Why all this interest in killing somebody? Are we really talking about what a beis din can do, or are we just enjoying talking about executing somebody? The Sanhedrin no longer sits in the Lishkas Hagazit, and until it does again we cannot use the death penalty. In fact, we no longer know exactly how judgment was made and how the sentence was carried out, only what the Gemara discusses, which doesn’t cover all the ground for practical application.
Enough fantasizing about this. Let’s think about something constructive – like preventing more tragedies, like maybe taking some of the stigma off mental illness so people won’t be afraid to take their family members who are seriously ill in for treatment.