Jill Valentine and Chris Redfield help found the BSAA in Resident Evil 5.
The Bioterrorism Security Assessment Alliance, usually abbreviated BSAA, is an international organization created to combat bioterrorism and biological weapons. Chris and Jill become central figures in its history after the collapse of Umbrella and the spread of bio-organic threats.
In Resident Evil 5, Chris works for the BSAA’s North American branch and Sheva Alomar serves in its West African branch. Their mission in Kijuju investigates illegal biological-weapons activity and leads to a confrontation with Albert Wesker.
S.T.A.R.S. is the police special unit from earlier games, while the FBC is a different counter-bioterror agency featured in Resident Evil Revelations. Neither is the organization founded by Chris and Jill.