It is not uncommon for someone to discover that they are under criminal investigation in a case that seems to have no end. Time goes by, months turn into years, and no charges are filed, no conclusion is reached, no definitive answer is given. The investigation remains open, silent, yet with very real consequences for the person under scrutiny.
In this context, a natural question arises: is this allowed? Is there a limit?
The legal answer is not simple — and the case law of the Brazilian Superior Court of Justice (STJ) shows exactly why.
The mistaken idea of a fixed deadline
Many people believe that a police investigation must be concluded within a strict legal deadline and that, once this deadline is exceeded, illegality is automatically established. This, however, does not reflect the STJ’s understanding.
When the person under investigation is not in custody, the statutory deadline for concluding the investigation is considered non-mandatory. In practice, this means that exceeding it does not automatically lead to nullity or dismissal of the investigation. The State is not required to conclude the inquiry exactly within that formal timeframe.
That said, this does not mean that the State’s power to investigate is unlimited.
Why this is not a mathematical issue
The STJ consistently rejects a purely chronological analysis because investigations vary greatly. Some cases are simple, others highly complex. Some involve a single individual, others multiple investigative fronts. Some progress quickly, while others require deeper technical examination.
For this reason, the Court applies a reasonableness test, examining the concrete circumstances of each case. Among the factors typically considered are:
- the total duration of the investigation
- the actual complexity of the case
- whether investigative steps have been effectively carried out
- the existence of periods of stagnation or inertia
- the conduct of the authorities involved
- the concrete impact of the investigation on the individual’s personal sphere
In other words, the analysis is not about counting days, but about assessing whether the time elapsed is still justified in light of what has actually been done — or left undone.
How the STJ has ruled on excessive delays in investigations
In HC No. 942,121/PE, the STJ examined an investigation that had remained open for nearly seven years. Despite multiple extensions, there had been no meaningful progress to justify its continuation. The situation was aggravated by the failure to comply with a previously imposed judicial deadline and by the lack of response to the Judiciary’s own requests for information. Faced with this combination of excessive duration and state inertia, the Court ordered the dismissal of the investigation, expressly affirming that the right to a reasonable duration applies to the investigative phase as well.
A similar reasoning was adopted in RHC No. 206,245/MT. Although the case was described as complex, the STJ made it clear that complexity alone is not enough. Judicial deadlines had been ignored, and long periods passed without proportional investigative progress. The Court emphasized that complexity does not justify inertia and ordered the investigation to be dismissed.
By contrast, in HC No. 926,111/SP, the request for dismissal was denied. Even though the investigation had lasted more than three years, the lower courts demonstrated that investigative steps were ongoing, that multiple individuals were involved, and that advanced investigative techniques were being employed. In this scenario, the STJ held that the mere passage of time, without evidence of unjustified stagnation, did not amount to unlawful constraint.
The decision in AgRg in HC No. 942,909/MG highlights how delicate this assessment can be. The investigation had been pending for over ten years. Even so, the majority of the Fifth Panel concluded that the formal existence of pending investigative steps and the absence of concrete prejudice to the investigated individual prevented dismissal at that moment. Notably, however, the decision was not unanimous. Dissenting opinions recognized that the investigation had been effectively paralyzed for years, revealing that even within the STJ there is a fine line between tolerance and abuse when time becomes excessive.
Finally, in HC No. 847,552/SP, the issue was not the length of the investigation itself, but judicial inaction. The STJ held that an unjustified delay in ruling on a defense request for dismissal also violates the right to a reasonable duration of proceedings. Although the Court did not close the investigation, it imposed a deadline for the trial court to rule, acknowledging that judicial silence may itself constitute unlawful constraint.
Conclusion
STJ case law conveys a clear message: not every long-lasting investigation is unlawful, but no investigation may continue indefinitely without concrete justification.
Dismissal due to excessive delay is an exceptional measure, but one that is entirely possible when an investigation ceases to progress, loses its legitimate purpose, and becomes a permanent state of uncertainty for the individual involved.
This is not a matter of mathematics. It is an assessment of reasonableness. And often, the right question is not how much time has passed, but what has actually been done during that time.
