“That is an insane number, three-times the amount of people there are in this world,” he said.
All right, he's not a mathematician. Caught the murderer anyway.
I might be tempted to vote “not guilty”
The sheriff is just lying out his ass, like he did when the previous innocent man was man was convicted in the case but later exonerated.
Random Match Probability (RMP)
This is the most common way results are presented at trial.
“What is the chance that a random, unrelated person would have this exact same DNA profile?”
High-Quality Profiles: For a full, 20-marker profile, the RMP is often one in a quadrillion or even higher—far more than the number of people on Earth.
40-Year-Old Samples: Because old DNA is usually degraded, you might only get a partial profile. This raises the RMP to perhaps as low 1 in 100,000.
While still strong, it means other people in a large city could technically match by sheer coincidence.