What must a valid warrant include?

A valid warrant must specifically include the name of the person to be arrested. This is essential because a warrant serves as a legal document that authorizes law enforcement to apprehend an individual. By naming the person, the warrant ensures that the police can only detain the specified individual, thus protecting against arbitrary arrests and ensuring compliance with due process under the Fourth Amendment.

In the context of the other choices, while the name of the police officer may be relevant for record-keeping or as an authorizing agent, it is not a constitutional requirement for the warrant's validity. Similarly, the time and date of the arrest are not mandated on the warrant itself, as the warrant is valid upon issuance, without needing these specifics. Lastly, the inclusion of witnesses to the crime is not necessary for the validity of a warrant; rather, warrants are typically based on probable cause determined through evidence presented to a judge, rather than the direct testimony of witnesses.