This was also part of a campaign in 2014/2015 in HK to stop people from leaving chewing gum on bus stop benches. [1]

The Virginia-based company then used its Snapshot DNA Phenotyping Service to extract strands of DNA from the trash and identify the person's "sex, ancestry, pigmentation (skin color, hair color, eye color, freckling), and even face morphology." That information was then used to create some insanely creepy 3D renderings of what each litterbug looked like. Parabon created 27 facial composites using 24 DNA samples collected from Hong Kong's streets and 3 from volunteers.

[1] - https://www.usatoday.com/story/travel/roadwarriorvoices/2015...