4.4 Significance of ABO Blood Types in Paternity and Crime Investigation

The ABO system (the Landsteiner discovery — the A, B, AB, O antigens; the secretor status): The paternity's era: the blood groups' exclusion-only power (the impossible combinations — the type-O-child-of-AB-parents' bar); the inclusion's weakness (the probability's coarseness — the millions sharing the type). The crime's use: the stains' grouping (the suspect's-and-victim's elimination-or-consistency); the pre-DNA era's workhorse (the cases' generations). The modern position: the DNA's displacement (U5) — the ABO's residual role (the rapid screening, the historical cases' re-examination); the exam's line: the blood group excludes, the DNA identifies. The prescribed cases' paternity line (cited verbatim; honest notes): the pre-DNA era's civil appeals — Pirtam Shah Kalwar v. Nagia Devi Kurmi (Civil Appeal No. 6922 of 2057 B.S., D.D. 2061/09/29 B.S.), Bahyai Lal Mahato v. Ram Kumar Mahato (Civil Appeal No. 5900 of 2056 B.S., D.D. 2061/04/29 B.S.) and Balkrishna Subedi v. Kunti Maya Chwai (NKP 2042 B.S., Decision No. 2573, D.D. 2042/11/20 B.S.) — the blood-group-and-paternity era's disputes (the courts' early handling of the biological evidence in the succession-and-status questions — read the reports for the precise holdings).