One of the most important things you can do after being arrested is contacting a qualified DUI attorney. One of the first things that should be done in an OUI case is for your attorney to send a preservation of evidence request out to the police department and DA's office. This puts everyone on notice that you want any and all available video and audio evidence in the case. That way, if the police fail to preserve the evidence as requested, your attorney has good grounds to get the breath test result excluded. This can have a HUGE and positive impact on your case.
Of course there are many reasons to contact my office immediately after arrest and this is just one example. However, it is a critical stage in the defense process and shouldn't be underestimated by either the client or the attorney.