Police don't need a search warrant to seize evidence when?

Answer 1

Most people believe that the police need a warrant to collect anything anywhere. But as long as the police officer has proable cause or a suspect gives consent to get a possible piece of evidence; they can collect anything. Another case is when there is an obvious, severe action being done.

Otherwise, the police must always get a warrant from a judge to search or collect anything.

Answer 2

When a police officer has reasonable grounds to suspect that a person is carrying or in posession of something, that person and his property can be searched. Reasonable grounds is defined as a set of facts or circumstances that would cause an ordinary, cautious, and prudent person to believe that an offence has occured. This belief must extend beyond mere suspicion. Example...I am a police officer that has stopped you for speeding. Upon approaching your vehicle, I smell marijuana smoke and see a haze of smoke in your car. This gives me reasonable grounds to suspect that there is marijuana somewhere in the immediate area, or your person, or in your vehicle. Thus, I have the lawful authority to search you, your car, your bags, etc until I am satisfied that there is or is not a controlled substance in your posession.

Answer:

This answer is specific to US Constitutional Law: Actually, the example of an officer smelling maijuana smoke at a traffic stop is "Probable Cause," that is he has seen (or in this case smelled) evidence that a crime has taken place. "Reasonable Suspicion" is the expectation that a crime has been commited without the clear existence of evidence. For instance, if the driver of the vehicle were to be sitting on his hands when the officer came up to the window, this could represent reasonable susicion that the driver was attempting to hide something, giving the officer authority to exit the driver from the vehicle and conduct a visual search. Note that during a visual search, the officer may not move any items to look under them; anything discovered must be in plain sight and not obscured. If he observed anything during the visual search, this would give him probable cause to conduct a more thorough search, which might lead to an arrest. The confusion that occurs in the differences between Probable Cause and Resonable Suspicion are not unique to civilians. Many law enforcement officers are unfamiliar, innocently or purposefully, to what constitutes legal search and detention.

In actuallity, the traffic stop itself give the officer authority to conduct a visual search on grounds of reasonable suspicion, and most do as they approach your vehicle. You will notice how they bend over to speak to you that their eyes scan the interior--this is the inspection. This is also the reason that heavy window tinting is illegal in most cities and states of the US.

Answer 3

When the evidence is in plain view.

Added: . . . or when conducting a consent search.