Final answer:
In this scenario, the police use the tactic of entrapment to arrest a suspect involved in an illegal exchange of drugs for sex at a motorhome in a public parking lot. The legality of this tactic and the admissibility of evidence depend on various factors including jurisdiction and the suspect's rights.
Step-by-step explanation:
In this scenario, the police have obtained evidence of an exchange of marijuana for sex. While this activity is illegal, entrapment is a police tactic that involves inducing someone to commit a crime they would not have otherwise committed. In this case, the police approached the suspect for sex and then arrested him. The legality of entrapment can vary depending on the jurisdiction, but it is generally considered unethical.
The police may use the confession obtained from the individual leaving the motorhome against him in court. However, the admissibility of evidence in court is subject to certain rules, such as the requirement for the police to inform the suspect of their rights, as protected by the Fifth Amendment to the U.S. Constitution. If the police did not inform the suspected drug dealer of his rights before interrogating him, his confession may be considered coerced and could be excluded as evidence.