When a crime is too old to prosecute, the legal term is the statute of limitations. It’s a law that sets the maximum time the government has to file criminal charges after an offense; once that deadline passes, the case is “time-barred” and a court can no longer hear it. For most federal crimes, that window is five years from the date of the offense.1Office of the Law Revision Counsel. 18 U.S. Code 3282 – Offenses Not Capital A handful of the most serious crimes, including murder, have no deadline at all.
What a Statute of Limitations Does
If prosecutors miss the window, charges can be dismissed no matter how strong the evidence is. The accused walks free. These deadlines exist for practical reasons: witnesses move away or die, memories fade, and physical evidence degrades. A prosecution built on five-year-old eyewitness testimony is far less reliable than one built on testimony from last month. The time limits push law enforcement to investigate promptly and spare people the stress of indefinite criminal exposure.
How Long Prosecutors Usually Have
Deadlines vary with the severity of the offense. Misdemeanors often carry windows of one to three years. Felonies run longer, from three years up to several decades depending on the crime and the jurisdiction. Federal law sets a baseline of five years for any non-capital offense unless Congress has specified a different period for that particular crime.1Office of the Law Revision Counsel. 18 U.S. Code 3282 – Offenses Not Capital
Congress has carved out longer windows for particular offenses. Major fraud against the United States carries a seven-year prosecution window.2Office of the Law Revision Counsel. 18 U.S. Code 1031 – Major Fraud Against the United States Federal tax crimes like evasion and filing a false return have their own time limits, often tied to when the fraudulent return was filed rather than when the income was earned. State felonies frequently run three to ten years depending on the offense category.
Crimes That Never Expire
Some offenses are considered so serious that the government can bring charges at any point, no matter how many decades pass.
- Capital offenses. Under federal law, any crime punishable by death can be prosecuted with no time restriction. This is why murder charges can surface 30 or 40 years after the killing.3Office of the Law Revision Counsel. 18 USC 3281 – Capital Offenses
- Terrorism offenses that caused or created a foreseeable risk of death or serious bodily harm.4Office of the Law Revision Counsel. 18 USC 3286 – Extension of Statute of Limitation for Certain Terrorism Offenses
- Certain war crimes, including those involving murder and torture.5Office of the Law Revision Counsel. 18 U.S. Code 2441 – War Crimes
- Sexual or physical abuse of a child under 18, which federal law allows to be prosecuted at any point during the victim’s lifetime, or for ten years after the offense, whichever is longer.6Office of the Law Revision Counsel. 18 U.S. Code 3283 – Offenses Against Children
States keep their own lists. Murder is nearly universal; legislatures have increasingly added sexual assault, kidnapping, and certain financial crimes against the government. The trend over the past two decades has been to expand the number of crimes that can be prosecuted indefinitely, particularly those involving children.
When the Clock Starts
For most crimes, the clock begins on the date the offense was committed. Hidden crimes complicate that approach. Financial fraud, embezzlement, and identity theft can go undetected for years because the perpetrator actively conceals what happened. Many jurisdictions apply the discovery rule, which delays the start of the clock until the crime is discovered or reasonably should have been discovered. An employee who embezzles over several years might not trigger the statute of limitations until an audit turns up the discrepancy.
Continuing offenses add another wrinkle. For a crime that spans months or years, such as an ongoing conspiracy or long-running fraud scheme, the clock typically doesn’t start until the last criminal act in the series.
What Pauses the Clock
Even after the limitations period starts running, certain events can pause it. Lawyers call this tolling. The clock freezes while the condition exists and picks up where it left off once it ends.
The most important federal tolling rule is blunt: the statute of limitations simply doesn’t apply to anyone fleeing from justice.7Office of the Law Revision Counsel. 18 USC 3290 – Fugitives From Justice A suspect who skips town or goes into hiding cannot run out the clock. Most states have parallel rules.
Crimes against minors trigger tolling in many jurisdictions. The clock may be paused until the child victim reaches 18, reflecting the reality that children often cannot report abuse or even recognize that a crime occurred.8FBI Law Enforcement Bulletin. Statutes of Limitation in Sexual Assault Cases Other common triggers include a defendant’s absence from the state and periods of mental incapacity that prevent a victim from pursuing the matter.
How DNA Evidence Can Reopen a Window
Advances in forensic science have created tension with these deadlines. Police may recover DNA from a crime scene but have no suspect to match it to, and by the time a database hit comes through, the prosecution window may have closed.
Federal law addresses this directly. When DNA testing later implicates an identified person in a felony, the statute of limitations is effectively restarted, giving prosecutors an additional period equal to the original limitation window, measured from the date the DNA implicated the suspect.9Office of the Law Revision Counsel. 18 USC 3297 – Cases Involving DNA Evidence
Some jurisdictions also allow John Doe indictments. Instead of naming a suspect, the charging document identifies the perpetrator solely by DNA profile. Because charges have been formally filed, the statute of limitations is satisfied. Once someone is eventually matched to that profile, they can be arrested and prosecuted regardless of how much time has passed. Courts reviewing the practice have found that a DNA profile is specific enough to meet the legal requirement that a warrant identify a particular person.
Raising the Defense
An expired statute of limitations doesn’t automatically kill a prosecution. The defendant or their attorney has to raise it, typically through a motion to dismiss filed before trial. If the defendant never raises the issue, the case can proceed as if no deadline existed, and a knowing and intelligent waiver of the statute of limitations is valid.10U.S. Department of Justice. Criminal Resource Manual 656 – Waiver of the Statute of Limitations
The analysis is rarely as simple as comparing two dates. A court has to evaluate whether tolling provisions applied, whether the discovery rule delayed the start of the clock, and whether the defendant’s own conduct paused the timeline. Prosecutors sometimes file sealed indictments before the deadline to preserve the case.11Congressional Research Service. Statute of Limitation in Federal Criminal Cases – An Overview
Civil Lawsuits Run on a Separate Clock
A crime that is too old to prosecute may still generate civil liability. Criminal and civil statutes of limitations are independent, with different deadlines, and one expiring has no effect on the other. Even if a prosecutor can no longer bring assault charges, the person who was harmed may still be able to sue for personal injury damages, provided the civil deadline hasn’t also expired. Civil windows for personal injury claims are commonly two to three years from the date of the injury, though they vary by jurisdiction. Fraud claims often run longer, sometimes six years or more, particularly when the discovery rule applies.