In Rodriguez v. US the SCOTUS held that a traffic stop resulting in a warning or citation that is prolonged beyond the time reasonably necessary to issue the paperwork can result in an unconstitutional detention. The reason this is a major decision as it relates to drug trafficking cases is obvious. In most situations an officer will conduct a traffic stop upon the motorist for a minor alleged violation. I typically see following too closely or improper lane use violations as the pretext to perform the stops. After the minor violation the officer requests the driver to accompany him/her back to the squad car to "complete the paperwork." While in the squad the driver is asked a battery of questions not related to the alleged violation whatsoever. The usual questions involve where the person is coming from and going to, who they were meeting at their destination, the purpose of the visit, what states they have travelled through (an essential element of trafficking), what hotels did they stay in, etc. In and of themselves the questions could seem like idle banter by the officer. However, the officer is in fact laying the foundation to establish in a court of law suspicious behavior which they will preface a vehicle search with.
After the citation/warning is issued the officer tells the subject they are free to leave. But just as the driver begins to walk towards his vehicle the officer says "Sir, do you mind if I ask you a few questions?' Most drivers will return and engage the officer in further conversation. He will advise that he is suspicious of the answers given by the driver. He will ask if everything in the vehicle belongs to the driver. Is there any money, drugs, or weapons located inside the vehicle? Ultimately he will request consent to search the vehicle.
At this point Rodriguez v US becomes relevant. If the driver says no I won't consent to a search and I will be on my way then a continued detention from that point forward may become unconstitutional. If the officer continues to detain the individual (doesn't allow him to leave) he may have violated the individual's 4th amendment right to be free of unlawful seizure.
The facts of Rodriguez are as follows: a police officer stopped a car for an improper lane violation. A Q&A session as described above took place. As the officer was issuing a written warning he asked permission (consent) to search the vehicle. Rodriguez stated no. The officer told Rodriguez to wait in front of the squad car until another deputy arrived on scene. The total time between the moment Rodriguez said "no" until the other deputy arrived on scene was only 5-6 minutes. The time that elapsed was minimal but very important to the SCOTUS. The Court ruled that the 5-6 minute prolonged detention was unconstitutional. The reason this is so important is that in Illinois various cases (both state and federal have held that continuing to detain an individual in such a situation is "de minimus" (not a constitutional violation) and would not result in a constitutional deprivation. Prior to Rodriguez delays of over 20 minutes after which time a warning or citation should have been issued was deemed non-violative of one's constitutional right. The SCOTUS gave judges a "bright line" rule that defines when a traffic stop must end. Should police choose to extend the length of such a stop they do so at the peril of losing evidence seized during the encounter.
It is easy to see why Rodriguez can result in suppressed evidence in many cases which fit the scenario given above. As a practitioner, I have seen this occur many times in the past. Some of those instances we were able to win despite Rodriguez not having been ruled upon at that time. Today, given this case, I anticipate many more successful motions to suppress evidence.