There is no fixed limit on how long you can be under investigation. Police and prosecutors can spend weeks, years, or in some cases decades building a case before deciding whether to file charges. The only hard deadline is the statute of limitations for the underlying crime, which caps how long prosecutors have to bring charges after the offense, not how long investigators can take to work the case. For most federal crimes that window is five years. For some state misdemeanors it is one. For murder and a handful of other serious offenses, there is no deadline at all.
The Statute of Limitations Is the Real Deadline
A statute of limitations sets the outer boundary on when a criminal case can be filed. It exists because evidence degrades and memories fade, and at some point it becomes unfair to force a defense against stale allegations. Once the period expires, prosecution is barred no matter how strong the evidence.
The federal default is five years for non-capital offenses.1Office of the Law Revision Counsel. 18 USC 3282 – Offenses Not Capital Congress has written longer windows for specific categories:
- Bank fraud, embezzlement from a financial institution, and mail or wire fraud affecting a financial institution: ten years.2Office of the Law Revision Counsel. 18 USC 3293 – Financial Institution Offenses
- Non-capital terrorism offenses: eight years.3Office of the Law Revision Counsel. 18 USC 3286 – Extension of Statute of Limitation for Certain Terrorism Offenses
- Child sexual or physical abuse: through the life of the victim, or ten years after the offense, whichever is longer.
- Terrorism resulting in or risking death or serious bodily injury: no limit.3Office of the Law Revision Counsel. 18 USC 3286 – Extension of Statute of Limitation for Certain Terrorism Offenses
- Capital offenses, including federal murder: no limit, ever.4Office of the Law Revision Counsel. 18 USC 3281 – Capital Offenses
State law is where the variation gets wide. Most states impose no limit on murder. Other felonies commonly fall in a three-to-ten-year band. Misdemeanors are often one to three years. Some states have removed limitations periods for all felonies or for entire categories of sex crimes. The clock generally starts running on the date the crime was committed, though specific offenses have their own accrual rules.
When the Clock Pauses
The limitations period doesn’t always run continuously. Federal law lets it stop, or “toll,” in a few situations.
The most common is flight. If you leave the jurisdiction to avoid prosecution, the clock stops until you return. The federal statute is blunt: no limitations period protects anyone fleeing from justice.5Office of the Law Revision Counsel. 18 USC 3290 – Fugitives From Justice
DNA identification is another. When DNA testing implicates a specific person in a felony, the limitations period is extended by an amount equal to the original limit. If a crime carries a five-year deadline and DNA identifies the suspect seven years in, prosecutors get another five years from that identification.6Office of the Law Revision Counsel. 18 USC 3297 – Cases Involving DNA Evidence
Why Investigations Drag On
Within the limitations period, how long an investigation actually takes depends mostly on the complexity of the alleged conduct. A straightforward assault with eyewitnesses might close in weeks. A fraud scheme routed through shell companies in multiple countries can consume federal agents for years, because the paper trail is enormous and the records are scattered across institutions and jurisdictions.
Several ordinary factors stretch timelines even in simpler cases. Forensic labs run backlogs, and analyzing a single computer or phone can take many months. Reluctant or unavailable witnesses slow things down. Cases that cross state lines or pull in both federal and local agencies require coordination that adds bureaucracy. Smaller agencies with heavy caseloads sometimes let less urgent files sit for months.
Federal investigations tend to run longer than state ones. The crimes are typically more complex, and the federal system leans heavily on grand juries, which spend months issuing subpoenas, taking testimony, and building the record before voting on an indictment.
What Protects You From Endless Investigation
The Constitution offers some protection against prosecutors sitting on a case, but far less than most people expect, and almost none of it applies before you are formally charged.
The Speedy Trial Act sets deadlines only after the charging stage begins: 30 days from arrest to indictment, 70 days from indictment to trial, with several exclusions.7Office of the Law Revision Counsel. 18 USC 3161 – Time Limits and Exclusions It doesn’t touch the investigation phase.
The Sixth Amendment’s speedy trial guarantee works the same way. The Supreme Court has held that the right attaches only at arrest or formal charge and runs through trial, not during pre-charge investigative delay.8Constitution Annotated. Overview of Right to a Speedy Trial
The only constitutional check on pre-charge delay is due process, and it is a hard argument to win. Under United States v. Lovasco, a defendant must prove two things: that the delay caused actual, concrete prejudice to the defense (specific lost evidence or unavailable witnesses, not just passage of time), and that the government delayed for an improper reason such as gaining tactical advantage.9Justia US Supreme Court. United States v. Lovasco, 431 US 783 (1977) Good-faith investigative delay does not violate due process even if it drags on and causes some harm. Courts generally defer to prosecutors who can show they were still actively working the case.
The practical takeaway: within the statute of limitations, the government has effectively as much time as it wants.
Finding Out Where You Stand
If you’re caught up in a federal investigation, one of the most important things to learn is how the government classifies you. The Department of Justice uses three categories. A target is someone against whom the prosecutor has substantial evidence linking them to a crime and who is essentially a putative defendant. A subject is someone whose conduct falls within the scope of the investigation but against whom evidence hasn’t reached target level. A witness is someone with relevant information who isn’t suspected of wrongdoing.10United States Department of Justice. Justice Manual 9-11.000 – Grand Jury
Targets often receive a target letter from the U.S. Attorney’s Office identifying them, referencing the statutes potentially involved, and advising them of the right to counsel. Receiving one does not guarantee charges, but it signals the investigation is advanced. Classifications can shift in either direction as evidence develops.
What if you’re never told anything? That’s common. Prosecutors are generally not required to notify you when they decide against charges. A declination might come as a formal letter, particularly in white-collar cases, or it might come as nothing at all. Your attorney can sometimes contact the U.S. Attorney’s Office to ask about status. Otherwise, silence is the more likely outcome, and it can last indefinitely. A case that isn’t formally closed but has run out of leads can also sit cold in a file, revivable if new evidence surfaces, a co-conspirator flips, or forensic technology advances. Cold cases have no expiration beyond the statute of limitations itself.
What to Do While You’re Under Investigation
The pre-charge stage is where people most often hand the prosecution its best evidence. A few rules matter more than any others.
Invoke your right to remain silent out loud. Under Salinas v. Texas, simply going quiet during voluntary police questioning does not invoke the Fifth Amendment; your silence can be used against you as evidence of guilt unless you expressly claim the right.11Oyez. Salinas v. Texas The safest phrasing is direct: “I’m invoking my right to remain silent and I want to speak with an attorney.”
Hire a lawyer as early as you can. The Sixth Amendment right to appointed counsel doesn’t attach until formal proceedings begin, so you don’t yet have a constitutional right to a free attorney during the investigation. But this is the stage where counsel matters most. A defense lawyer can communicate with prosecutors, advise on whether to sit for an interview, and sometimes negotiate a resolution before charges are ever filed.
Do not talk to investigators without counsel. You aren’t required to. Absent a court order or grand jury subpoena, you can decline. And if you do talk, know the trap: under 18 USC 1001, making a false statement to a federal agent is itself a felony carrying up to five years, even if the underlying investigation never produces charges.12Office of the Law Revision Counsel. 18 USC 1001 – Statements or Entries Generally People sit down for a “voluntary” interview, get nervous, shade the truth on some detail they think is minor, and end up charged for the lie rather than the underlying conduct.
Do not destroy documents, delete files, or ask anyone else to. Obstruction and evidence tampering are serious offenses on their own and can carry heavier penalties than whatever was being investigated in the first place.