Definition
*Propter delictum* (Latin: "on account of crime") is a ground for challenging a juror based on the juror's prior conviction of or disqualifying involvement in criminal conduct. It is a species of challenge for cause — a formal objection to a prospective juror's service on grounds that the law recognizes as creating legal disqualification, rather than merely raising suspicion of bias. Under this ground, a party may seek to exclude a juror whose criminal record or infamy renders them incompetent to serve as a matter of law, without exhausting a peremptory challenge.
The challenge *propter delictum* is distinguished from other grounds of challenge by its basis: it is not about the juror's relationship to the parties or the case, nor about mental or physical incapacity, but specifically about a moral or legal taint arising from the juror's own criminal history. At common law, conviction of an infamous crime — one involving moral turpitude or punishable by death or infamous punishment — was treated as a permanent mark against the juror's competency, operating almost automatically rather than requiring a showing of actual prejudice.
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Common Confusion
*Propter delictum* is one of several Latin grounds for challenge for cause and is easily confused with *propter affectum* (challenge on account of bias or partiality toward a party) and *propter defectum* (challenge on account of legal defect or disqualification, such as alienage, infancy, or lack of property qualification). The three together constitute the classical common law taxonomy of challenges for cause. In modern practice, the distinctions have largely collapsed into a single statutory or procedural category of "challenge for cause," but the Latin labels remain relevant when reading older cases and treatises. A researcher encountering *propter delictum* in a historical source should not assume the court is discussing juror bias toward a party — that is *propter affectum*, a separate and analytically distinct ground.
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Recognized Forms
/SUBTYPES
At common law, challenges for cause were organized into three principal categories, of which *propter delictum* is one:
- **Propter defectum** — challenge on account of general legal disqualification (e.g., alienage, non-citizenship, infancy, lack of freehold qualification)
- **Propter affectum** — challenge on account of partiality or bias, actual or presumed, toward a party or the subject matter
- **Propter delictum** — challenge on account of the juror's own criminal conduct or infamy
These categories appear consistently in Blackstone and in the major nineteenth-century American treatises on evidence and jury practice. The tripartite framework is the organizing principle for challenge-for-cause analysis in historical sources.
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Why It Matters in Research
Researchers working with pre-twentieth-century trial records, pleading books, or appellate opinions on jury selection will encounter *propter delictum* as a live procedural category, not merely an antiquarian term. Understanding that it refers specifically to criminal disqualification — and not bias generally — is essential to correctly interpreting what a party was arguing when invoking it.
The practical significance of *propter delictum* declined as states codified juror qualifications and moved away from common law rules of infamy toward specific statutory lists of disqualifying convictions. Modern statutes in most jurisdictions disqualify convicted felons from jury service by operation of law, making the formal challenge *propter delictum* largely redundant: the disqualification operates before voir dire rather than through challenge. A researcher tracing the evolution of felon juror exclusion rules should recognize *propter delictum* as the common law antecedent to these modern statutory provisions.
The corpus connection to run is *propter delictum* alongside *propter affectum* and *propter defectum* — these terms travel together in historical jury practice materials. Any source that uses one is likely to use the others nearby. The entry point in secondary historical sources is typically under CHALLENGE, as both Black's and Rapalje & Lawrence direct, rather than under its own heading.
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Historical Dictionary Support
Black's Law Dictionary defines the term tersely as "for or on account of crime," identifying it as a species of challenge, and cross-references the CHALLENGE entry for substantive treatment. Rapalje & Lawrence are equally spare: "on account of crime," with the same cross-reference to the challenge entry. Both sources treat *propter delictum* as a heading of organization rather than a term requiring independent elaboration — its content lives in the challenge entries, not here.
Neither source elaborates on what level of criminal conduct sufficed to support the challenge, leaving that question to the treatise literature. Blackstone's *Commentaries* (Book III, Chapter 23) provides the fuller common law account: conviction of treason, felony, or any "crimen falsi" — crimes involving fraud or false statement — were the paradigmatic bases. American courts in the nineteenth century applied the concept variably, with some requiring an actual conviction and others treating mere infamy or indictment as potentially sufficient grounds in extreme cases.
What the historical dictionaries miss: neither Black's nor Rapalje & Lawrence addresses the decline of *propter delictum* as a distinct category or its relationship to emerging statutory felon-exclusion rules, which was an ongoing development in American jurisdictions at the time of both publications.
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Jurisdictional Note
The relevance of *propter delictum* as a distinct, named challenge is essentially historical across all U.S. jurisdictions. Modern felon exclusion operates by statute or court rule as a categorical disqualification rather than through a challenge procedure. Researchers working in New Jersey historical materials should note that Rapalje & Lawrence flag New Jersey specifically in the underlying challenge entry, suggesting the tripartite challenge taxonomy had some particular currency in that jurisdiction's practice literature.
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