Here is the full list of all 21 RICO achievements.
Reach level 14
Get a kill with a side arm, tactical weapon, and a grenade in the same room
Neutralise three or more criminals with one stinger in the same room
Complete a case on Hard difficulty
Revive another player five times
Purchase all the weapons
Revive yourself five times
Get one thousand kills
Complete a case
Knock off 50 masks
Finish three operations losing less than ten health
Get five hundred kills
Get twenty melee kills
Survive ten waves in lockdown mode
Survive five waves in lockdown mode
Complete a daily training session
Knock down a criminal sliding into a room
Get one hundred kills
Clear a room while in slow-mo ten times
Complete a two-player operation
Complete a daily operation