The District Director of the Internal Revenue Service (IRS) will decide whether a reward is warranted for the person providing the information. When it comes to investigator's assisting the IRS in conducting an investigation, remember that the suspects are more afraid of the IRS than their criminal charges. The Fourth Amendment mandates that any arrest or search conducted by the police must be based on probable cause and that the probable cause must exist at the time of the arrest or search. Depending on the type of investigation investigator are conducting, they may have a variety of ways to put their search warrant together. It is recommended that investigator always look at the use of financial elements within their warrant. When a vehicle is the target of the search warrant, it must be described in such a manner that it can be distinguished from all others of the same year and manufacturer.