Polydactyly is a condition in which a person is born with extra fingers or toes. The term comes from the Greek words for “many” (“poly”) and “digits” (“dactylos”). There are several types of polydactyly. Most often the extra digit grows next to the fifth finger or toe. Polydactyly tends to run in families.
https://www.google.com/search?q=six+fingered+hand&tbm=isch&source=univ&fir=OzdtWjD6I9BERM%252CYDe0n9MyXdFbSM%252C_%253Bzc0NiWXzYdzFaM%252CtSuHubk5TvbEXM%252C_&usg=AI4_-kQnh772luH16pK55I7udr-5jZ3HeQ&sa=X&ved=2ahUKEwj-6-CU44z9AhUc-DgGHeuECHkQ7Al6BAgIEAM&biw=1280&bih=613&dpr=1.5
And why would a police force make special equipment for one single person?
We don't know if that glove was police issued. But sure.