[Nervous Tick]

RE: Serino’s opinion that Z was telling the truth:

In the abstract, I can understand why a witness’ opinion might be off limits in seeking to establish fact — hence an objection by the prosecution.

However, Serino’s JOB in interrogating Z was to get at the truth, by any means necessary. Therefore, since that what exactly what he was SEEKING TO DO, and since he’s a professional (expert?) PAID to do just that, why should his CONCLUSION not be admissable?

[Cboldt]

In principle, it’s the witness encroaching on the province of the jury. Truth of a witness’ testimony is for the jury to decide, not for another witness to decide.

[XenaLee]

"...why should his CONCLUSION not be admissable?"

I think we all know the answer to that. And it has nothing to do with justice or fairness, much less with the goal of ensuring a fair trial for Zimmerman.

[CA Conservative]

However, Serino’s JOB in interrogating Z was to get at the truth, by any means necessary. Therefore, since that what exactly what he was SEEKING TO DO, and since he’s a professional (expert?) PAID to do just that, why should his CONCLUSION not be admissable?

I agree, especially since Serino's opinion about a suspect's truthfulness will directly affect how he conducts his investigation, whether to file charges, etc. He is not stating whether or not what the suspect told him WAS the truth - just his impression or opinion of what the suspect told him.