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