Civil Security Bosses are the most powerful Civil Security unit, thus the name boss. They have as much health, if not more, as the Marine. They carry almost every weapon, even all of them sometimes. They are very hard to take out. They first appear in Level 18 and begin sparsely appearing in other levels. They debuted in Level 40, as every enemy is a Boss.
Bosses wear green and red and are referred to as zombies in some custom maps. They basically look exactly like Lites, except that their backpacks have an antenna and their armor's coloring. They have very heavy armour but can still run fairly fast. It can withstand CS-BNG and Rocket Launcher hits. They are fairly easy to stop. Bosses are the highest ranking unit in the Security.
Bosses carry heavy weapons such as the Heavy Railgun v04 CS-OneSOneK, the CS-BNG, Plasmagun CS-Bloom and the Rocket Launcher CS-LitBro. They like to camp and will try to subdue you with their Rocket Launchers. Then, they move in for the kill with the CS-Bloom and the CS-BNG. Other Civil Securitys wound you by attacking you.
Rather than immediately taking them out, you should take out the Lites and Heavies so you can focus on destroying the Bosses. You can also hurt them with barrels and grenades. Don't try to kill them with psi swords, or they'll destroy you.
Bosses try to take you out with heavy weapons and appear in groups of two or more to stall you. At Level 40, the only enemy is the Boss, but with a group of 3, you can somewhat easily kill them all. The only real problem for you is their Drone Guns and Ray Guns. On the other levels that they appear in, shoot them in the feet with an assault rifle or a semi-auto shotgun. Even better, use the Rocket Launcher CS-LitBro or the Plasmagun CS-Bloom.