Amazon Rekognition falsely matches 28 members of Congress to arrest photos in ACLU test

Summary

The ACLU built a face database from about 25,000 public arrest photos with Amazon Rekognition, using Amazon's default match settings, and searched it against photos of every sitting member of the House and Senate. The tool returned 28 false matches. The false matches fell disproportionately on people of color, including six members of the Congressional Black Caucus. The test used an 80 per cent confidence threshold, Rekognition's default; Amazon responded that it now recommends 99 per cent confidence for uses such as police mugshot searches.

Consequence

• Amazon responded that it now recommends a 99 per cent confidence threshold for important uses such as police mugshot searches

Who caught it A researcherFound outside the organization

This is a study: context for the failures library rather than an incident at one organization, so it carries no lesson.

Key dates

1. July 26, 2018Event
2. October 16, 2026Checked against sources
3. October 21, 2026Checked against sources

Developments are added when the record is reviewed. Next review: October 16, 2027.

Evidence

Each passage is quoted from its source. The quoted passages are re-checked against the live pages every month.

1. Our test used Amazon Rekognition to compare images of members of Congress with a database of mugshots. The results included 28 incorrect matches. The false matches were disproportionately of people of color, including six members of the Congressional Black Caucus

   Supports: test, 28 false matches, disproportionate errors for people of color

   Amazon's Face Recognition Falsely Matched 28 Members of Congress With Mugshots American Civil Liberties Union Primary source

2. The ACLU set their code to require an 80 per cent or higher confidence to match a face, the default setting for Rekognition. Amazon's Matt Wood has blogged in response to the ACLU study, saying the web giant now recommends 99 per cent confidence

   Supports: default threshold used; Amazon's response

   Politicians fume after Amazon's face-recog AI fingers dozens of them as suspected crooks The Register Reporting or analysis