In some states, a pre-trial deposition (sworn testimony from key state witnesses taken down verbatim by a court reporter), can be requested by your attorney. Also, as part of your administrative license suspension (or revocation) hearing, your attorney may be able to use civil “discovery” tools such as a “notice to produce” (to compel documents or tapes to be turned over), “requests to admit” certain facts, or other civil forms of discovery to uncover favorable evidence. In some jurisdictions, the use of pre-trial “civil” depositions of police officers may be available for your attorney to use.
The primary purpose of forcing the state to reveal or turn over 100% of any available items that will (or could be) used to help prove your case at trial is that your skilled DUI-DWI defense attorney knows that the “smoking gun” that wins your case may be found in these materials. Additionally, any pre-trial hearings or depositions that require your police officers to give sworn testimony “locks in” key testimony from them for your trial when it later gets scheduled. This can lead to the impeachment of the officer and possibly cause his or her total collapse on the witness stand.