A quick definition of John Doe warrant:

A John Doe warrant is a type of warrant that allows law enforcement to arrest someone whose name is unknown. It may be used for a person known by sight but not by name. Other types of warrants include arrest warrants, search warrants, and extradition warrants. A warrant is a legal document that authorizes someone to do something, like make an arrest or conduct a search. It is important that warrants are issued only on probable cause and meet the Fourth Amendment's specificity requirements. A warrantee is a person who receives a written warranty.