In the field of law, a warrant is a writ issued by a competent officer, such as a judge or magistrate, authorizing law enforcement officers to execute a particular task, which can otherwise amount to violation of individual rights enlisted in the Fourth Amendment of the U.S. Constitution. Warrants should not to be confused with summons; the latter only order the individual to appear in court on a specified date, failing which an arrest warrant can be issued in his name. A search warrant is a type of warrant that authorizes law enforcement officers to search a person, location, or vehicle for evidence. In the United States, the Fourth Amendment makes it clear that law enforcement officers require a warrant based on 'probable cause' to search an individual or his property for evidence, or to make an arrest. In the case of a search warrant, the probable cause can be any information that warrants a prudent person's belief that the evidence of crime or contraband will be found in search. The Fourth Amendment also states that the search should be specific and reasonable. By specific, it means that the warrant should have the details of individuals who are to be searched (as well as the property that is to be searched) clearly specified in it. The law enforcement officer may have to get an additional warrant to search a vehicle, if the one issued to search the home doesn't have the vehicle specified in it. Similarly, searching an individual who is not specified in the list, will also require an additional warrant. The reasonableness factor comes into the picture when it comes to the knock-and-announce rule and no-knock warrants. While the knock-and-announce rule, which states that the officer has to knock and announce his arrival and give the occupant enough amount of time to open the door, does exist, it is not inflexible, and therefore, the law enforcement officer can break it if he thinks it would be reasonable to do so. Despite the fact that it is on the officer's discretion to follow the knock-and-announce rule, such that he may choose to not follow it, there also exists a specific provision to issue no-knock warrants. In this case, the law enforcement officer has to prove to the judge that the no-knock warrant is justified. In a drug-related case, for instance, if the officer feels that the knock-and-announce rule will give the suspect enough time to destroy the evidence, then he can ask for a no-knock warrant. In some cases, law enforcement officers anticipate that at some point of time in the future, they will get some evidence that will help them incriminate the suspect. In such cases, the concerned officer can opt for an anticipatory warrant. Then there is the delayed notice warrant, also known as the sneak and peek search warrant, which allows law enforcement officers to enter the private property without the occupant's knowledge and search the premises. At times, delayed notice warrants act as precursors to traditional search warrants. Nighttime searches are only permitted in certain cases. That may, however, differ from jurisdiction to jurisdiction. In the case of federal investigation, investigating officers are not supposed to carry out a search between 10:00 PM and 6:00 AM. Then again, it will depend on the seriousness of the issue. Furthermore, a search warrant may not even be required if the person gives his consent in case of an emergency or during hot pursuit. An arrest warrant, as the name suggests, is a warrant that authorizes a law enforcement officer to arrest and detain an individual. In the United States, to arrest an individual, the officer requires a probable cause to arrest, which will be any information that warrants a prudent person's belief that the wanted individual has committed some crime, and a valid arrest warrant. The validity of the warrant will depend on two things: (i) whether it has been issued by a neutral magistrate, and (ii) whether the affidavit on which it is based contains falsehoods, known or otherwise. An arrest warrant contains the specifics of the accused, i.e., the name (John Doe, in case the name is not available) and description, brief information about the alleged offense, and the specific order that the said individual should be taken into custody. The warrant will remain active until the individual is arrested, in which case it will be considered an outstanding arrest warrant. This will also apply to cases in which the individual on whose name the warrant has been issued against is unintentionally avoiding the law enforcement agency unaware of the warrant against him. A bench warrant is issued to arrest an individual who is in contempt of court for his failure to appear before the judge on the assigned day. If you cannot make it to court, you should at least make it a point to send someone on your behalf, failing which the judge can issue a bench warrant against you. An execution warrant, or death warrant, authorizes the execution of death penalty after the convict has been sentenced to death by the trial court. The competent authority―usually the trial court judge―issues the execution warrant and sends it to the Department of Corrections, which is in charge of carrying out executions. In federal cases, the task is carried out by the U.S. Bureau of Prisons. While the date of execution is assigned by the court, the authority to decide the time of the day to execute the sentence lies with the Department of Corrections. After the execution warrant is signed, the convict is moved from the death row cell to the death watch cell. The warrant expires after a specific period, in which case the convict is moved back to the death row cell where he awaits the new date. Besides these, there are warrants which are issued by authorities which have a jurisdiction over a larger area and thus, these warrants are valid over a larger area. The European Arrest Warrant (EAW) which is valid throughout all member states of the European Union (EU) is an apt example of this. Then there is the Interpol Red Notice, which is used to locate, arrest, and extradite international fugitives from member countries. Considering that the Interpol has 190 member states, the Red Notice is as good as an international arrest warrant.