Police can conduct a sting operation, if that's what you mean by "legally lie".
"Pull over, house visit" makes no sense.
The above is general legal and business analysis. It is not "legal advice" but analysis, and different lawyers may analyse this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in California. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here.
In most places in the US, the police are allowed to lie to subjects as long as they are not on the witness stand under oath. Therefore, if an undercover officer tries to buy drugs from you, and you ask if he is an officer, he can lie and say no, and you have no remedy for this lying. However, in Michigan, recent case law makes clear that the judge cannot authorize a witness to lie on the stand, even to protect the witness from physical harm.
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