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