When police arrest someone, the law permits them to conduct what is known as a search incident to arrest, even if they do not have a search warrant. This allows them to search the suspect’s pockets and personal belongings such as a purse, shopping bag or wallet, in order to check for weapons and prevent the destruction of evidence.

But until very recently, it was unclear whether police could look at the contents of an arrested person’s cellphone as a part of a search incident to arrest. Now, however, the U.S. Supreme Court has settled the issue with a resounding “no.”

A typical modern cellphone contains so much personal information that the Court reasoned a cellphone search is more comparable to going through a suspect’s entire home from top to bottom than sifting through the contents of his or her briefcase. Therefore, the Court concluded unanimously, a warrant is usually required before police may conduct a cellphone search — the same standard that applies to home searches.

An important thing to keep in mind when dealing with police is that they do not need a warrant to search your cellphone, car, home or belongings if they have your permission. Many people consent to searches in the hopes of appearing cooperative, only to then be arrested and charged on the basis of what the search reveals.

If you are stopped by police, remember your rights and avoid doing anything that might help them establish probable cause to arrest you. If you are arrested, politely but firmly state that you are invoking your right to remain silent and that you wish to speak with your attorney.

Source: The Wall Street Journal, “Supreme Court: Police Need Warrants to Search Cellphone Data,” Jess Bravin, June 25, 2014