The Evidence was a beta vehicle in Grand Theft Auto: Liberty City Stories and Grand Theft Auto: Vice City Stories. Nothing is known about this vehicle apart from unused GXT Lines. It was probably meant to be used in the mission L.C. Confidential.
Judging from its possible appearance in L.C. Confidential, it seems to have been a coroner van. The vehicle GXT in Grand Theft Auto: Vice City Stories suggest a possible mission similar to L.C. Confidential was scrapped early in development.