Text Messages as Evidence
Here are a couple bits from that article:
This was cast into the light recently when the defense in the Kobe Bryant sexual assault case announced that they may investigate text messages sent among Bryant's accuser, a former boyfriend, and another friend.
Text messaging is a store-and-forward technology. One person types a message and sends it to the service provider (Cingular, T-Mobile, Verizon, etc.). The provider then sends that message to the intended recipient. This is much the same way e-mail works. And in most circumstances, there's some record of the information contained in these messages left on the server.
Source: TVC Alert