Today, more so than ever perhaps, the exact definition of your rights preventing illegal search and seizure are in flux. Recent decisions have impacted how police may search you and your property. Theoretically speaking, the Fourth Amendment of the United States Constitution curtails the amount of authority law enforcement officials have to make invasive searches and seize items from citizens. Search and seizure law, however, has undergone constant legal precedents set in the courts and legislation that further expands law enforcement's ability to conduct surveillance on citizens, especially in light of concerns regarding terrorism.
In essence, the fourth amendment seeks to protect the privacy rights of private citizens from government officials. The terms illegal search and seizure only apply to law enforcement or government officials, and in many instances it may be illegal, other private citizens, such as your landlord, employer, or even private security personnel have free range in invading your privacy, if they are prepared to accept any criminal penalties applicable to their actions.
The specific terminology of the amendment provides protection from "unreasonable searches and seizures". Immediately following this, however, the amendment provides government officials the right to conduct search and seizure if "upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized". These terms essentially created what is known as the modern search warrant that judicial officials may issue to law enforcement with due and probable cause. There are a number of legal precedents and facts surrounding what constitute illegal search and seizure, which include:
In spite of protections provided in the fourth amendment, law enforcement officers (noted in actual wording as "government officials") are reserved the right to conduct searches under the grounds of probable cause. Today, in essence, this requires law enforcement officers to present their probable cause reasons to a member of the judicial department, which will issue a warrant to search the property. However, search warrants are not a carte blanche invitation to invade privacy, but rather a legally executed search warrant must include:
One of the most frequently contested issues is the validity of the "probable cause" to issue a warrant. In many cases, the precedents regarding these laws vary highly, but it is important to note that searches conducted under a search warrant that is later determined not valid can still be used as evidence in some cases. In addition, law enforcement is restricted to look for certain items in a specific location in a search warrant, so if a warrant issues a search for weapons in a shed in your backyard, and police search your home as well, the search in the home is illegal. Also, if a warrant specifically allows law enforcement to look for automatic weapons in your home, and police officers somehow find a small amount of heroin in your light switch plate, the heroin will probably be deemed not legally seized, although don't expect to get your dope back.
In essence, if a law enforcement officer asks to enter your home, search your person, or vehicle and you consent, you pretty much give up your right to challenge the legality of any seizure or search because you "consented" to a search. Additionally, law enforcement does not need to inform you of your right to refuse a consented search, so, they can prove insistent until an individual consents without legal consequence. However, the consent must be given "freely and voluntarily", so instances of fraud, coercion, and even undue duress may constitute illegal searches. Numerous other circumstances can also surround a consented search, and generally, only an experienced attorney is truly versed enough to challenge search or seizure.
If a law enforcement officer has a legal right to be in plain sight or can smell parts of illegal contraband, they have the right to seize the contraband or evidence and arrest individuals. However, if an officer finds the items illegally, contraband may be seized, but cannot be used as evidence in criminal courts.
In order to search a vehicle following a traffic stop, officers must have probable cause to commence a search. Again, "probable cause" is a relative term determined by a litany of legal court rulings at the appellate level usually. Also, officers can perform at "stop and frisk", which essentially allows them to pat down your person as a means of protecting the officer's safety, according to Terry v. Ohio, 1968.