# Hidden multiple comparisons increase forensic error rates

## TL;DR

This paper highlights how comparing wire cut surfaces in forensics can lead to higher error rates due to multiple comparisons, similar to other forensic practices.

## Contribution

The paper introduces the concept of hidden multiple comparisons in wire cut surface analysis, a novel perspective in forensic error analysis.

## Key findings

- Comparing wire cut surfaces involves multiple distinct comparisons, increasing false discovery rates.
- The issue is analogous to database searches in forensics, which also face multiple comparison challenges.

## Abstract

When wires are cut, the tool produces striations on the cut surface; as in other forms of forensic analysis, these striation marks are used to connect the evidence to the source that created them. Here, we argue that the practice of comparing two wire cut surfaces introduces complexities not present in better-investigated forensic examination of toolmarks such as those observed on bullets, as wire comparisons inherently require multiple distinct comparisons, increasing the expected false discovery rate. We call attention to the multiple comparison problem in wire examination and relate it to other situations in forensics that involve multiple comparisons, such as database searches.