Most people carry a cellphone every day. Many do not realize that the phone may also create location records. In California, prosecutors frequently use those records in serious criminal cases. Learning how digital location evidence works can help people evaluate the strength of the prosecution’s case.
How investigators obtain location data
A cellphone may connect to nearby cell towers as it moves from place to place. It may also create location data through GPS, Wi-Fi and some mobile apps. These records can help show where a phone was at certain times.
Under federal constitutional law (Carpenter v. United States) and the California Electronic Communications Privacy Act (CalECPA), law enforcement officers generally must obtain a search warrant based on probable cause before securing historical cell tower or GPS location records from service providers. Once they receive the records, they compare them with other evidence. That comparison helps shape the investigation.
How prosecutors use location records
Prosecutors often use location data to build a timeline. They compare it with other evidence, such as:
- Surveillance video
- Witness statements
- Financial records
- Vehicle location data
- Phone calls and text messages
Under California law, prosecutors must prove every part of a criminal charge beyond a reasonable doubt. Location data alone usually cannot prove that someone committed a crime. Instead, it helps support or challenge other evidence. Looking at all the evidence together gives the court a fuller picture. Even then, the records may face questions.
Why location data is not always conclusive
Cellphone location data is not perfect. Cell tower data indicates only a geographical radius, rather than an exact location. GPS records may also vary in accuracy. Courts may also examine whether law enforcement obtained the records lawfully under a valid warrant and handled them properly after collection. If investigators gathered the data unconstitutionally, the defense may file a motion to suppress that evidence.
These questions can affect how much value the court gives the evidence.
Cellphone location data can play an important role in serious California criminal cases. Still, it is only one piece of the evidence. As cell tower and GPS data are subject to legal challenges and technical inaccuracies, reviewing how investigators obtained your records is a critical step in building a California criminal defense.
