This list isn't exhaustive but many of these are civilian gangs, so it's probably a case of both.
There are of course corrupt members of law enforcement who collaborate with organized crime for various nefarious purposes, but the in-department gangs are a distinct issue.
It specifically mentions armed services, police, and firefighters are not civilians.
Civilian in law enforcement jargon means a non-sworn position: https://www.discoverpolicing.org/explore-the-field/civilian-...
To make this more interesting, Posse Comitatus employs the language to signal "non-Federal forces" eg: National Guard activated by a state to operate domestically are referred to as "civilian law enforcement".
In any of the above cases, calling LEOs civilians would be incorrect and would eschew them of many of their responsibilities.