According to the knock and announce rule, what is a reasonable amount of time to wait before an officer may break and enter?
According to the knock rule, officers have to knock and announce that they're officers with a search warrant before they enter the place about to be searched. To determine what is a reasonable amount of time a test is performed, which is reasonableness based on the totality of circumstances in an individual case. Two to four seconds probably aren't reasonable, ten to twenty usually are (Lafave,2004,673-674). The test come about from the case U.S. v. Spikes,1988,926 where the 6th U.D. Circuit of Appeals stated that" the Fourth Amendment's 'knock and amnounce' cannot be distilled into a constitutional stop-watch where a fraction of a second assumes controlling significance". (Samaha, p.199-200)

Give an example of a third parry consent search and why it would be valid.
An example of a third party consent would be if law enforcement asks a roommate to search an area in which both parties are entitled to, such as the living room and the roommate gives consent. This example is valid because it is authority consent which comes from "mutal use of the property by persons generally having joint access or control for most purposes, so it is reasonable to to recognize that any of the co-inhabitants has the right to permit the inspection in his own right and that others have assumed the risk that one of their numbed might permit the common area to be searched"