As part of S.T.A.R.S’ (Special Tactics and Rescue Service) Bravo Team, Richard Aiken is encountered in both Jill and Chris’ playthroughs, and his fate in the game rests upon the choices you make.
As you head towards the attic, you will see Richard stumble across your path in a pretty bad way. As he explains, he has been bitten by a giant snake and requires the serum that he didn’t bother to pick up before. Head back to the medical storage save room and examine the shelves there to find the serum. Take it back to Richard and use it on him. This will save Richard from dying from the snake bite, but he won’t necessarily see it through the rest of the game. What saving him does do, however, is create a set of variants of how he actually dies, all surrounding self-sacrifice. If you save him as Jill, he will sacrifice himself to save Jill during the battle with Yawn. If you give him the serum as Chris, Richard will again sacrifice himself, this time to save Chris from a Neptune shark.
There are a couple of other scenarios to play out regarding Richard’s death. If you take too long getting the serum he will eventually succumb to his poisoned wounds, and if you leave the Yawn fight with the death mask before beating it, Richard will stay behind and is eventually killed.
Unfortunately, there isn’t really a way to save him from dying completely, but you can prolong his life for a short while. Plus, if you managed to get the serum to him on time you will receive his trademark assault shotgun once he does die. Every cloud, right?