Technology changes quickly, but the law changes slowly. Police have adopted new technology to investigate crimes, and courts have struggled to figure out how to apply the law to these new situations. The result can set up a showdown with the Fourth Amendment.
The Fourth Amendment
The Fourth Amendment to the U.S. Constitution provides some of the most important protections available in criminal defense. It provides that we must be free from “unreasonable search and seizure.”
Over the centuries, courts have had to figure out what makes a search or an arrest “unreasonable,” and what to do about it when it happens. These interpretations are always changing, but for the most part, they have settled on the idea that police need a warrant supported by probable cause in order to search a person’s home.
There are many exceptions to this rule, but warrants are crucial parts of many criminal investigations, including drug crime investigations.
If a court finds that police violated a defendant’s Fourth Amendment rights by executing a search without a warrant, then, for the most part, any evidence they obtained in that search must be suppressed. This means the prosecution can’t use that evidence in its case against the defendant.
Probable cause and technology
As noted above, a search warrant must be supported by probable cause. This means that police must show a magistrate judge that they have reason to believe that they will, more likely than not, find evidence of a crime at a specific location. They must be specific about where they will search and what they are looking for.
To get this kind of information, police have traditionally relied on their own observations and the word of informants.
Technology is always creating new ways for them to observe people in order to gather evidence, and courts have struggled to figure out the place of this new technology under the law. For instance, almost a century ago, the Supreme Court ruled that police need a warrant to get a wiretap on a defendant’s phone. A little more than 20 years ago, the Supreme Court ruled that police had violated the Fourth Amendment rights of a defendant when, without a warrant, they pointed heat-sensitive infrared cameras at his house in an effort to detect marijuana-growing equipment.
In more recent years, the Supreme Court has ruled that the Fourth Amendment limits the ability of police to put a GPS tracking device on a suspect’s car, or to look through a suspect’s smartphone.
Skilled criminal defense attorneys keep track of these changes in technology and the law and help their clients see how the Fourth Amendment can apply to the facts of their cases.