MBE Fast Fact: Knock and Announce

The rule requiring that a police officer knock and announce his/her presence prior to executing a warrant is a bit convoluted. On the one hand, it's stated that police officers are required to do this, but on the other hand, MBE questions often claim that a failure to do so will not trigger the exclusionary rule. It's best to think of the knock and announce rule as one that is not absolute. Police officers will not be required to knock and announce their presence prior to executing a valid search warrant if:

(1): there is potential that occupants are going to flee;

(2): there is potential that evidence will be destroyed; or

(3): there is potential harm to the police officers if they are required to knock and announce their presence.


At least one of the three considerations above will almost always apply on the MBE, and therefore you should assume that the 4th Amendment exclusionary rule (preventing any seized evidence from getting admitted during trial) does not apply where the police have a valid search warrant, and where the only violation was a failure to knock and announce their presence.