Definition
The place where a crime was committed. Locus criminis is a Latin phrase used in criminal law and procedure to identify the physical location at which an offense occurred. The concept is foundational to several practical legal determinations: which court has territorial jurisdiction to try the offense, which sovereign's law governs, and where venue properly lies.
The term operates at two levels. As a factual matter, locus criminis is simply the geographic site of the criminal act. As a legal matter, identifying that site triggers a cascade of jurisdictional and procedural consequences — particularly when crimes are committed across state or national borders, or when the acts and their harmful effects occur in different places.
Why It Matters in Research
The phrase appears most frequently in older treatises, appellate opinions addressing venue or jurisdiction disputes, and extradition materials. Researchers working in nineteenth- and early twentieth-century criminal law reports will encounter locus criminis as a standard term of art; by the mid-twentieth century, American courts increasingly substituted plain English equivalents ("place of the crime," "situs of the offense"), though the Latin persists in scholarly writing and in courts with strong common law traditions.
The most important research trap is conflating locus criminis with venue as a procedural rule. Locus criminis is the underlying factual and legal concept — where the crime happened. Venue is the procedural mechanism that flows from it. Historical sources sometimes treat them interchangeably; they are not the same thing.
For multi-jurisdictional crimes — fraud schemes, conspiracies, crimes committed near state lines, or offenses where the act occurs in one place and the result in another — courts have disagreed about how to fix the locus criminis. Some jurisdictions locate it at the place of the act; others at the place where the criminal result was felt. Researchers should not assume a single settled answer across sources or time periods. Treatises on conflict of laws in criminal matters and extradition law are the most useful corpus connections.
The term also appears in international criminal law contexts, where locus criminis helps determine which national court or tribunal has competent jurisdiction. Historical materials on extradition treaties frequently invoke it.
Historical Dictionary Support
Both Black's and Bouvier's offer nearly identical, stripped-down definitions: the locality or place where a crime was committed. This agreement reflects that locus criminis was never a contested concept at the definitional level — what it means has always been clear. What historical sources largely omit is the analytical difficulty that arises in practice: crimes that unfold across multiple locations do not have a single, obvious locus criminis, and the question of how to fix it has generated substantial case law that neither dictionary addresses.
Bouvier's entry, consistent with its mid-nineteenth-century vintage, treats the term as self-explanatory. Black's is equally terse. Neither source engages the multi-jurisdictional problem or the distinction between locus criminis and venue. For that analysis, researchers must move past the dictionaries to treatises and appellate opinions.
The Latin form remained standard in American legal writing well into the twentieth century and continues to appear in international and comparative law materials today, reflecting the term's origins in civil law and canon law traditions where Latin terminology was preserved longer than in common law pleading.
Jurisdictional Note
American federal courts and most state courts recognize that for crimes with elements occurring in multiple places, identifying the locus criminis requires a choice-of-law-style analysis. The constitutional venue requirement under the Sixth Amendment anchors trial in the district where the offense was committed, making the locus criminis determination a constitutional question in federal prosecutions, not merely a procedural one. International materials, particularly extradition treaties, may apply civil law concepts of locus criminis that differ from common law usage.