I have a trial in two weeks on a theft case where the defendant stole an item that the complainant had placed a GPS device on.

Do I need to have some sort of expert witness to explain the GPS? If so, who? If so, is there a predicate that anybody has?

Or, has GPS become scientifically acceptable enough that I can merely ask the complainant about the system he used and ask him about the coordinates that he was getting notifications of?

Please help...running out of time. If more details about the case are needed, please ask.

Brown v. State 163 S.W.3d 818 Tex.App.–Dallas,2005

Should help

A question, just out of curiosity. . . Are you adding the cost of the GPS device to the value of the item, for theft purposes?

The personnel from your 911 addressing system at your local council of government may have someone that may be able to assist you in explaining how the GPS system works.

Ask the judge to take judicial notice of Wikipedia:

Details.

You can even rely on Wikipedia for that concept:

Details.

(Of course, I'm kidding.)

Turns out Wikipedia is a good enough source for at least one court of appeals. Check out footnote 1 in this opinion.