Definition
A Latin term meaning "to follow up," "to pursue," or "to prosecute." In legal usage, prosequi does not function as a standalone doctrine but as a root term embedded in several procedural phrases that carry independent legal significance. It appears most prominently in:
1. NOLLE PROSEQUI — A formal entry by a prosecutor (criminal) or plaintiff (civil) declaring they will not further pursue the case or a particular count. The operative phrase; the term most researchers will actually encounter.
2. NON PROSEQUITUR — A judgment entered against a plaintiff in a civil action for failure to prosecute, such as failure to file a required pleading within the prescribed time. Literally, "he does not prosecute." Abbreviated non pros.
Common Confusion
Prosequi itself is rarely the operative legal term. Researchers who encounter it in historical sources are almost always looking at a fragment of nolle prosequi or non prosequitur. Treating prosequi as a freestanding doctrine rather than as a Latin root shared across distinct procedural instruments will produce misdirected research. The two derived phrases are not variants of the same concept: nolle prosequi is a voluntary act of abandonment; non prosequitur is an involuntary judgment imposed for procedural default.
Why It Matters in Research
Prosequi surfaces in the Law Mind corpus primarily as a Latin root within compound phrases rather than as a term of art in its own right. Researchers should be alert to several navigational points:
First, indexing and cross-referencing in historical sources is inconsistent. Some dictionaries and treatises lead with the full phrase (nolle prosequi, non prosequitur) while others index the component Latin word and force the reader to follow a cross-reference. When searching historical materials, querying the root prosequi may surface entries that a phrase-level search would miss.
Second, Bracton's usage — preserved in Burrill and reflecting thirteenth-century common law — frames prosequi as the conceptual opposite of exceptio (the plea or defense). Bracton's distinction between "following after another" (the plaintiff's prosecuting posture) and "being followed by another" (the defensive posture) is a structural observation about the adversarial frame, not a procedural rule. Researchers working in early common law sources or in historical legal theory will encounter this framing; it should not be imported into modern procedural analysis.
Third, the civil and criminal applications of derived phrases developed along different tracks. Non prosequitur is essentially a civil procedural instrument tied to default for failure to act; nolle prosequi originated in both civil and criminal contexts but became predominantly significant in criminal practice as prosecutorial discretion doctrine developed. Conflating these tracks in historical research produces anachronism.
Fourth, in older English practice, the phrase appeared in writs and pleading records in abbreviated or variant forms. Researchers reading manuscript court records or early printed law reports may encounter prosequi in abbreviated Latin without the full compound phrase intact.
Historical Dictionary Support
The historical dictionaries converge on the core meaning — "to follow after; to pursue or prosecute" — without meaningful disagreement. The variation lies in depth, not substance.
Black's (both editions) treats prosequi as a brief Latin gloss and immediately redirects to nolle prosequi, signaling that the term's practical legal value is derivative. This is the right editorial instinct but produces thin standalone coverage.
Anderson's is more revealing in what it inadvertently shows: the entry for prosequi is partially corrupted in surviving text, with what appears to be material from an unrelated entry (prostitution) interleaved. Researchers relying on Anderson's for this term should verify against other sources. Anderson does usefully note the non prosequitur application — judgment against a plaintiff for failure to file a declaration — making it the most procedurally grounded of the historical entries despite the textual confusion.
Burrill's is the most substantive for historical research purposes. The citation to Bracton (fol. 98b) is genuine and the conceptual framing — distinguishing the prosecuting plaintiff from the defending respondent as a structural matter — reflects the medieval common law understanding of adversarial process. Burrill's entry is the appropriate starting point for anyone working in early English legal history.
None of the historical dictionaries provide adequate coverage of the criminal procedure dimension of prosequi's derivatives, particularly the constitutional and discretionary aspects of nolle prosequi that became significant in American practice. That doctrine developed substantially after the period these dictionaries primarily reflect.
Jurisdictional Note
The procedural instruments derived from prosequi — particularly nolle prosequi — vary significantly across American jurisdictions in their scope, court approval requirements, and effect on double jeopardy analysis. Several states have replaced or supplemented the common law nolle prosequi with codified dismissal procedures. Non prosequitur as a distinct judgment has been largely absorbed into modern default and dismissal rules under codes of civil procedure.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Nolle Prosequi; Non Prosequitur; Prosecutorial Discretion