If police have enough evidence to suspect you're involved in a crime they may ask a judge to approve a search warrant allowing them to enter your home or place of business and retrieve evidence.
Search warrants are limited to specific hours, such as 6 a.m. to 9 p.m., unless the judge or magistrate allows police to alter that timeframe. You do not have to be home for them to execute a search warrant on your property, because a warrant allows them to enter without your permission.
A search warrant specifies the evidence police are seeking, whether a computer, drug manufacturing equipment, stolen property, child pornography, or burglary tools. They are supposed to confine their search to those specific items and not go through other parts of your house or belongings that are unrelated to that search warrant, but the law allows them to seize items they can claim were "in plain sight" such as narcotics left on a table, or even large sums of cash they can argue were part of the drug sales, pornography, or burglary crimes you're accused of.
Yes, police may search without a warrant if: someone lets them into the house or office they want to search; if they are in "hot pursuit" of a suspect and chase him into the building where items related to a crime are located, or if they believe the public is in imminent danger, such as of a drug manufacturing lab on the premises exploding.
Since 2001 when the federal Patriot Act was enacted police and federal law enforcement have increasingly used so-called delayed notice or "Sneak and Peek" warrants which allow them to break into a home or business and search for evidence in advance of an actual search warrant being signed by a judge. These "Sneak and Peek" warrants have been used to build cases against drug manufacturers and dealers and do not require police to notify the occupants that they have been in a home or business.
A warrant is a legal document that is signed by a judge. There are a variety of types of warrants, including search warrants, arrest warrants, and bench warrants. Warrants direct law enforcement (local police, sheriff's deputies, or even state police or F.B.I. in the case of a federal warrant) to perform a specific task within a specific period of time, often two weeks from the date it's signed. Those tasks may involve collecting evidence for a criminal or civil trial, arresting a person wanted for a crime, or bringing in a fugitive who has avoided mandatory court proceedings.
Search warrants require police to prove first to the judge or magistrate that they have sufficient reason to believe the premises in question contain evidence of a crime. A judge will not sign and approve a search warrant unless the argument provided by police meets the necessary threshold of evidence.
Police and courts rely on warrants to build cases against criminals. Courts rely on warrants to perform necessary judicial duties, such as holding hearings at which the defendant must be present. Some jurisdictions have experienced an overwhelming number of unserved warrants, and this backlog of work resulted in courts erasing whole categories of warrants, such as misdemeanor warrants over two years old.
You may call your local law enforcement officials to find out if there's a warrant out for your arrest or for the search and seizure of items in your home. In some cases it might be less disruptive to your family and beneficial to your defense in court if you surrender yourself or your belongings to the court and cooperate rather than wait for police to find you with a warrant.