The Maryland Supreme Court issued a ruling that strengthens protections for drivers against traffic stops based on ambiguous cell phone use, holding that police officers need more than basic observations of phone handling to justify pulling over motorists.
In *State of Maryland v. Michael Eugene Stone*, decided in September Term 2025, the state's highest court applied the Fourth Amendment's reasonable suspicion standard from *Terry v. Ohio* to determine when officers can lawfully stop vehicles for suspected mobile phone violations. The court concluded that simply observing a driver "manipulating, touching, or pressing screen of mobile phone, without additional information" does not provide sufficient justification for a traffic stop.
The case centered on Maryland Transportation Code sections 21-1124, 21-1124.1, and 21-1124.2, which govern mobile phone use while driving. Under these statutes, certain uses of mobile phones while operating a vehicle are prohibited, while others remain lawful.
The Supreme Court of Maryland emphasized that to justify a traffic stop under the Fourth Amendment, police officers must be able to "credibly identify specific facts, not applicable to general law-abiding public, which, taken together with rational inferences from those facts, under totality of circumstances, reasonably establish that violation" has occurred or may be occurring. This standard derives from the landmark *Terry v. Ohio* decision from 1968, which established the framework for reasonable suspicion in police encounters.
The court's analysis focused on the ambiguous nature of basic phone handling while driving. The justices determined that limited observations of drivers touching or manipulating phone screens "are equally consistent with lawful mobile phone use and therefore do not eliminate substantial portion of innocent drivers or supply particularized facts required to justify stop" under the relevant transportation code sections.
This ruling reflects the practical reality that modern smartphones serve multiple functions, many of which drivers can legally access while operating vehicles. For instance, drivers may lawfully use hands-free calling features, navigation systems, or emergency functions that require touching the device. The court recognized that without additional context, an officer cannot reasonably distinguish between permitted and prohibited phone use based solely on observing screen contact.
The decision originated from the Circuit Court for Washington County in case C-21-CR-23-000386. The case was argued before the Maryland Supreme Court on Oct. 3, 2025, with Chief Judge Fader and Judge Watts among those hearing the matter.
The ruling establishes a higher evidentiary threshold for traffic stops involving suspected mobile phone violations. Officers must now point to specific, articulable facts that suggest illegal phone use rather than relying on general observations that could apply to law-abiding drivers. This might include observing typing motions, extended periods of visual attention to the device, or other behaviors that more clearly indicate prohibited activities like texting or browsing.
The decision aligns with broader Fourth Amendment jurisprudence that requires police to have particularized suspicion rather than general hunches when conducting investigatory stops. The *Terry* standard demands that officers be able to point to "specific and articulable facts" that, combined with rational inferences, suggest criminal activity.
For law enforcement, the ruling means traffic stops for mobile phone violations must be supported by more detailed observations and documentation. Officers will need to note specific behaviors that distinguish potentially illegal phone use from permitted activities. This could include observing drivers holding phones to their ears without hands-free devices, witnessing obvious texting motions, or noting extended periods where drivers' attention is diverted to their devices.
The practical impact extends to thousands of Maryland drivers who use phones legally while driving. The decision protects against pretextual stops where officers might use ambiguous phone handling as justification for broader investigatory purposes. It reinforces that constitutional protections apply even during routine traffic enforcement.
Legal observers note the ruling reflects courts' ongoing efforts to balance effective law enforcement with privacy rights in an era of ubiquitous mobile technology. As smartphones become increasingly integrated into vehicle systems and daily life, courts must carefully define when their use crosses from legal to illegal territory.
The *Stone* decision joins a growing body of case law addressing how traditional Fourth Amendment principles apply to modern technology. Courts nationwide continue grappling with similar questions as mobile device use while driving remains a significant traffic safety and legal enforcement issue.
The ruling will likely influence how Maryland law enforcement agencies train officers on mobile phone traffic enforcement. Police departments may need to update their protocols to ensure stops meet the heightened standard established by the court's interpretation of reasonable suspicion requirements.