~~~ The undated documents show that federal agents are trained to “recreate” the investigative trail to effectively cover up where the information originated, a practice that some experts say violates a defendant’s Constitutional right to a fair trial. If defendants don’t know how an investigation began, they cannot know to ask to review potential sources of exculpatory evidence - information that could reveal entrapment, mistakes or biased witnesses. ~~~

If you believe any of "fruit of the poisonous tree" stuff makes any difference, I've got a bridge to sell you. There is clear evidence that DEA agents are trained to create a "clean" story of evidence around the illicit information they get.