Which of the following requires a search warrant and is not allowed incident to arrest?

A search warrant is a legal document that allows law enforcement to conduct a search of a specific place or to seize certain items. In the context of this question, a search warrant is typically required for actions that involve a higher expectation of privacy, such as obtaining blood samples or body fluids.

The correct response indicates that all the scenarios listed necessitate a search warrant, which is accurate because they all involve obtaining bodily samples that are considered highly personal and private. In the case of a blood sample for typing from a suspected rapist, consent or a warrant is necessary as the individual has a right to privacy regarding their bodily fluids. Similarly, obtaining a public hair sample requires a warrant due to the sensitive nature of the material and the potential for violation of privacy rights.

For a blood sample taken to determine the presence of alcohol after an accident involving an unconscious driver, while exigent circumstances might apply in certain situations, generally, law enforcement is required to obtain a warrant due to the invasive nature of drawing blood.

Thus, the need for a search warrant across all scenarios emphasizes the importance of protecting individuals' rights while conducting investigations and underscores the legal standards law enforcement must uphold when collecting evidence.