Defendant is being tried for sexual assault of a child. Defendat has prior conviction for assault family violence of this same child. Clearly, that is admissible under 38.37. My question is, can I admit the judgment of conviction against the defendant in the guilt phase of the trial to show that Defendant pleaded guilty to FV on victim. Or, do I have to rely solely on victims testimony?

The rule regards relevancy as to the relationship dynamics between the defendant and victim, but a judgment doesn't explain those details beyond the fact that the defendant was convicted of violence against the child. The testimony of the child or another competent adult can explain it better. However, if the defense attorney makes the child (or other witness) look like a liar about the former situation on cross-examination, or if for some reason you have a judge that will exclude the testimony without proof of a conviction (not required by the rule, but still...), then I would be sure to have the judgment ready as a backup. Realistically the jury probably doesn't need to know at the guilt phase what he previously got as punishment; they just need to know that the relationship was a violent one (which can help explain why the child might not have told someone sooner, etc.).

I certainly plan on exploring the entire situation with the victim, and agree that he is the best source of information about that relationship.

It just seems to me that the judgment shows that, not only is the victim/witness saying he was abused by the Defendant, but that Defendant has previously pleaded GUILTY to abusing the victim. That proves the extraneous beyond a reasonable doubt, and reassures the jury that we "aren't just taking the word of the child" as to the prior bad acts.

The only issue might be that if the defense attorney doesn't really cross the child on those issues (i.e., doesn't paint the child's testimony as untruthful), you might run into a cumulative evidence problem. Not saying the judge would grant that objection, but it's something to think about for appeal purposes. The attorney also could offer a stipulation to the effect that the defendant has pleaded guilty, but again, that doesn't really explore the whole story.