Richard's memento is an article in Resident Evil Recollections. It was uploaded on 11 December 2014.
Richard is miraculously pulled back from the brink of death after being bitten by the enormous snake Yawn in the mansion.
He drops an assault shotgun after sacrificing himself for the player later on, and it feels kind of wrong to enjoy using it so much considering his sacrifice but I just can't help myself!
It's best used against Zombies by letting them get close and aiming high, you'll know when it's worked!