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