I bet I am not wrong about the groups in front being police/military, though. Probably firefighters too, but I bet the SWAT team signed up.
"Teams can sign up for one of four divisions: Public Safety Division (police officers, firefighters, military, etc.), School Division (students/school-affiliated teams), Disability Division (individuals with disabilities), or Open Division (general public). Teams can include family members, friends, co-workers, gym buddies, or other community members. The event is designed for participants of all abilities and ages."