What is the test for exclusionary rule in the "fruit of the poisonous tree" doctrine?

The purpose of the "fruit of the poisonous tree doctrine" is to exclude derivative evidence obtained from an initial illegal search. (People v. Werner (2012) 207 Cal.App.4th 1195, 1213.) If law enforcement conducts an illegal search and obtains incriminatory information, the use of that illegally obtained information affects the downward chain of all other evidence obtained from that source. For example, if a police officer uses the illegally obtained information and seeks a search warrant, the subsequent search and any evidence obtained in the secondary search may be subject to exclusion under the fruit of the poisonous tree doctrine.

The policy for the exclusionary rule is to deter police misconduct. (United States v. Leon (1984) 468 U.S. 897, 909.) It is a judicially created rule, where once the trial court determines police misconduct has occurred, the court excludes the evidence obtained from the misconduct to prevent similar misconduct in the future.