Final answer:
A search warrant is necessary when entering a third party's house to serve an arrest warrant to ensure compliance with the Fourth Amendment of the United States Constitution. However, there are exceptions to the search warrant requirement based on consent, exigent circumstances, or plain view. Evidence obtained without a valid search warrant may be deemed inadmissible in court.
Step-by-step explanation:
When entering a third party's house to serve an arrest warrant, a search warrant is usually required. This is because the Fourth Amendment of the United States Constitution protects individuals from unreasonable searches and seizures. The search warrant ensures that law enforcement officers have probable cause, supported by an oath or affirmation, to search the premises and seize any persons or property related to the arrest warrant.
However, there are exceptions to the search warrant requirement. For example, if one occupant of the house consents to the search while another objects, the police cannot conduct a warrantless search. Additionally, if there are exigent circumstances or if evidence is in plain view, a search without a warrant may be justified.
It is important to note that the exclusionary rule applies to evidence obtained illegally through an unlawful search or seizure. This means that if evidence is obtained without a valid search warrant, it may be deemed inadmissible in court.