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