minor4th
Verified Attorney
- Joined
- Jan 14, 2013
- Messages
- 8,529
- Reaction score
- 5,223
This is confusing. These are either legal definitions - or they aren't. From everything I'm reading (journal papers) - the jury is out. The psych community wants this to be a legal definition, but I don't see (yet) where that has been formally established.
So it's basically an opinion of this mental health expert, but the DT is going to (imv) try to present it as legal fact - an equivalent to the definition of manslaughter vs. murder 1. I can't find anything that says this is true... still looking.
No witness should be allowed to give an opinion on an issue of ultimate fact -- such as whether a murder was premeditated or not, as that is the exclusive province of the jury. The judge will not allow such opinions from experts or anyone else in front of the jury.
Likewise, experts are not permitted to opine about the truthfulness of a witness for the same reason.