Orin Kerr writes:
I recently posted a draft of a new article, Cross-Enforcement of the Fourth Amendment, forthcoming in the Harvard Law Review. Here’s the opening:
Imagine you are a state police officer in a state that has decriminalized marijuana possession. You pull over a car for speeding, and you smell marijuana coming from inside the car. Marijuana possession is legal under state law but remains a federal offense. Can you search the car for evidence of the federal crime even though you are a state officer?
Next imagine you are a federal immigration agent driving on a state highway. You spot a van that you have a hunch contains undocumented immigrants. You lack sufficient cause to stop the van to investigate an immigration offense, but you notice that the van is speeding in violation of state traffic law. Can you pull over the van for speeding even though you are a federal agent?
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