Exhumed body DNA tests can establish paternity with over \(99.99\%\) probability when DNA is successfully recovered.

However, success relies heavily on environmental conditions and sample quality.
If successful, exclusions are \(100\%\) certain.

Key Factors Affecting Accuracy and Success Degree of DNA Degradation:
1. The environment in which the body was buried is the biggest factor. Bodies buried in dry, cool, or heavily embalmed environments yield better results. Warm, moist, or highly acidic soils cause rapid DNA fragmentation.
2. Source of the Sample: Post-mortem samples degrade quickly. Laboratories generally require 2 grams of bone (e.g., femur or humerus) or teeth (which protect DNA from environmental exposure) rather than soft tissue.
3. Sample Contamination: Exhumed remains are susceptible to bacterial or fungal contamination and cross-contamination from surrounding soil, complicating the extraction process.
4. Number of Markers Tested: Accuracy depends on testing a high number of genetic markers to build a reliable profile, which is more difficult with degraded samples.
5. Standard Probability MetricsInclusion: If the profiles match, laboratories calculate the Combined Paternity Index (CPI) and report a probability of paternity (POP) typically exceeding \(99.99\%\).Exclusion: If the DNA profiles do not match at key markers, the man is excluded as the father with \(100\%\) certainty.

Alternatives to Exhumation:
Because exhumations are complex, expensive, and legally demanding, many forensic experts first explore alternative methods.
1. Biological Evidence: Utilizing retained biological samples (such as blood or buccal swabs taken before death), stored personal items (e.g., a used toothbrush or razor), or previously collected tissue blocks.Relative DNA 2.Reconstruction: Reconstructing the deceased’s DNA profile by testing living relatives (parents, siblings, or the mother of other offspring).