Aggravated sexual assault of a child case going to trial on the 25th of January. Defendant denies sexual assault, but admits to meth use on the day of allegations.

Two extraneous allegations involving adult victims, but all victims are family members and one of the adults is extremely mentally handicapped.

Ex-wife will testify that defendant's weird sexual proclivities started after he started using meth.

Any suggestions for someone who could testify as an expert on how sex offenders don't always necessarily target children, but prey on helpless individuals who are less capable of protecting themselves or saying no. I think we have found a couple of experts locally who can talk about how meth users generally act sexually based on their work undercover, but it would also be great to find a chemist who could explain why that happens.

Any ideas and suggestions would be greatly appreciated.

From the sexual deviancy side of things, we use Ezio Leite with PSY in Fort Worth as our expert witness.