The Fourth Amendment gives adequate protection to a citizen preventing his being stopped and questioned for DUI or any other offense unless the Police Officer presents compelling evidence or probable cause for his action. By virtue of this ruling an Officer cannot pull over a vehicle arbitrarily and has to be justified in following through with traffic stop procedures. Merely suspecting criminal behavior or following up idle curiosity is not sufficient grounds for a traffic stop. There must be clear cut violation of the law or clearly discernible infringement of rules or a visible pattern of erratic driving before the decision can be taken to pull over a vehicle.
Typically, a Police Officer pulls over a vehicle if there is a violation of the vehicle code or any other law, and it is not necessary that the violation should only be related to impaired driving. An equipment violation such as a broken or faulty brake light or an illegal window tint can force an officer to halt the vehicle. If on stopping the vehicle and after questioning the driver, the officer gains the impression that there is a DUI violation, he will follow up the procedures for investigating and arresting the errant driver.
The California Vehicle Code Section 21658(a), laying down its “lane straddling” statute is the subject matter of frequent violations, especially when the driver is suspected for DUI. According to the law a driver is expected to observe lane discipline and remain reasonably within his lane throughout his journey till it is considered safe to change the lane. Over speeding or inability to stick to lane discipline and frequent swerving in and out of lanes can create grounds to suspect the DUI offense. If unusual or suspiciously erratic driving behavior is detected, the Police Officer is well within his responsibilities to follow through a traffic stop.
Further, courts have clearly ruled that if the driver shows inability to drive in a uniform manner within the same lane and is observed to be weaving uncontrollably within the lane this is sufficient reason to justify a traffic stop and to initiate a DUI investigation in the proper manner and as per laid down procedures. But this rule cannot be stretched to include minor variations in movement within the lane or a onetime crossing of the lane demarcation. The illegality arises only when there is a pattern of weaving motion that raises suspicion of DUI.
Traffic collisions can also create grounds for suspecting whether one of both of the drivers involved was driving under the influence. Where it is not possible for the officer to directly witness the collision and know for certain the probable cause for the accident, it will become necessary to enquire the reasons from both the parties and to question eye witnesses at the scene. If it is suspected that a driver was under the influence of liquor or narcotics at the moment of collision, a separate DUI investigation needs to be launched on the spot, and this would mean detaining the driver or both drivers and further the DUI booking process.
It is commonly known that the human body has only a limited tolerance for liquor and intoxicants and that beyond a certain point (legally defined as BAC exceeding 0.08) the mind-body connect visibly falters leading to impaired driving, creating grounds for serious road accidents. The traffic stop is designed to diffuse potentially dangerous situations that could claim lives and damage property. At the same time there is adequate constitutional protection safeguarding citizens from abuse of authority and illegal traffic stops. 1800Bail 12912 Brookhurst St #415, Garden Grove, CA, 92840 (657)218-5432