Definition
A Latin term used in old pleading to denote an accessory — that is, a person who assists, enables, or participates in the commission of a crime without being the principal actor. The term appears in formal pleading contexts where Latin was the language of legal instruments, and functions as the Latin equivalent of the English "accessary" (the older spelling) or "accessory." In charging documents and indictments of the relevant period, ACCESSARIUS identified the secondary party to a criminal act, distinguished from the principal who physically committed it.
Common Confusion
ACCESSARIUS should not be confused with ACCESSORIUS, though Burrill himself cross-references the two as interchangeable. The distinction, to the extent one existed, was one of spelling convention rather than substantive legal difference. Both terms denoted the same legal concept in Latin pleading. Modern researchers should also note that the archaic English spelling "accessary" and the now-standard "accessory" refer to the same legal role; the spelling variation is historical, not meaningful.
Why It Matters in Research
This term matters almost exclusively as a research bridge. Encountering ACCESSARIUS in a historical document — an indictment, plea roll, or procedural treatise — signals that the document is working within the Latin pleading tradition, typically predating the full transition to English in legal instruments. The term itself carries no doctrine that differs from the substantive law of accessories; it is a Latin placeholder for a concept fully developed under English criminal law.
Researchers working in early criminal records or pleading manuals should be aware of three navigational points. First, the term points forward to ACCESSORY and ACCESSORIUS as the substantively richer entries — look there for doctrine on the distinction between accessories before the fact, accessories after the fact, and principals. Second, the cross-reference in Burrill to Townshend's Pleadings (Pl. 49) suggests the term was a live pleading term in practice guides, not merely a theoretical Latin gloss. Third, the term's appearance in a charging document may affect how jurisdiction over the accessory was asserted, since historical rules on where an accessory could be tried tracked the location of the principal's act — a trap for researchers reading venue or jurisdictional arguments in old indictments.
Historical Dictionary Support
Burrill's treatment is minimal and explicitly deferential: ACCESSARIUS is defined simply as "accessary; an accessary," with a citation to Townshend's Pleading and an immediate cross-reference to ACCESSORIUS. Burrill offers no independent doctrinal content under this heading. This is consistent with the entry's function as a Latin form entry rather than a substantive one — Burrill catalogs it to help practitioners recognize the term in old documents, not to expound on the law of accessories. No other shelf source in the present corpus takes up ACCESSARIUS as a distinct entry, which confirms that the term had no independent legal life beyond its role as a Latin pleading form.
What the historical dictionaries collectively omit: none address the procedural consequences that could flow from charging someone as ACCESSARIUS versus principal, nor do they discuss how the pleading requirement to name the principal before charging an accessory interacted with cases where the principal was unknown or fled. Researchers needing that doctrine must move to the substantive entries on ACCESSORY and to historical treatises on criminal pleading.