The Impact of Social Media on Criminal Cases: What You Should Know

Social media can be a powerful tool in court and is often used as evidence in criminal cases. Posts, comments, private messages, and even online associations—such as being mutual followers—can all be introduced as evidence. Privacy settings do not make content immune from legal scrutiny; even private accounts can be subpoenaed if the information is relevant to the case. As a result, anything shared online—publicly or privately—may be used against a defendant in court.

Both law enforcement agencies and prosecutors increasingly utilize social media as a critical tool in building cases. They use posts, messages, and online interactions to establish timelines, identify suspects, and uncover potential admissions of guilt. Monitoring social media platforms for indications of illegal activity or suspicious behavior has become standard practice within many police departments. A 2023 survey of police departments further emphasized this trend, reporting that social media is regarded as an important resource for investigating crimes occurring both online and offline.¹

Law enforcement reviews public posts in search of illicit activities but can also operate undercover by creating fake profiles or using real accounts. In some cases, individuals may even provide their account access to law enforcement, allowing officers to pose as that person. This tactic can be used to elicit incriminating statements, messages, or photos and videos, which can later be presented as evidence.

Posts that are not thought to be incriminating at the time of the post can later become highly damaging. Posts or comments intended as jokes or hyperbole can easily be misinterpreted or taken out of context. For example, phrases like “I’d kill for pizza right now” or “If you don’t text me back, I’ll kill you”—though likely meant sarcastically—can be viewed as threatening language if scrutinized. 

A notable example of social media’s role in criminal prosecution is the case involving two 14-year-old boys convicted of murder. Investigators uncovered that the pair had used Snapchat to coordinate their attack. Saved voice notes and messages revealed explicit discussions about their plans, providing clear evidence of premeditation. Although the boys attempted to delete these communications after the fact, digital forensic experts were able to recover the deleted messages which secured critical evidence that contributed to their conviction.

Social media significantly affects jury impartiality and trial fairness. In high-profile cases, the media often publicizes a defendant’s social media before a verdict—known as “trial by media.” This can lead jurors and the public to form biased views of guilt or innocence. Although jurors are instructed not to research or discuss the case outside the courtroom, the pervasive nature of social media complicates this. Jurors may unintentionally encounter biased content influenced by online posts, comments, or coverage, undermining the trial’s integrity.

There are several important takeaways regarding social media use, especially when facing legal scrutiny. Above all, exercise extreme caution with what you post online. Avoid sharing your location or tagging locations in real-time, as this can provide unintended evidence. Refrain from saving stories or posts that could later be reviewed or subpoenaed. Keep all accounts set to private and limit interactions with unfamiliar users. 

Most importantly, never send or share any potentially incriminating messages, images, or videos. A commonly overlooked but critical point: do not delete posts, messages, or media that could be relevant to an investigation or trial. Deletion can be interpreted as consciousness of guilt and may trigger additional charges such as obstruction of justice or destruction of evidence. In the digital age, every post leaves a trail—one that can easily be retraced in a courtroom.

Aniela J. Giarmo, is a Legal Intern at The Law Office of James L. Riotto and is a student at the University of Rochester Class of 2027.