Complex sentence: Another possibility is for overtly uniformed security forces to punish a victim, but under circumstances that make it appear as self-defense, such as by planting recently-fired weapons near the body, or fabricating evidence suggesting suicide.
Split into simpler sentences: Another possibility is for uniformed security forces to punish a victim, but under circumstances that make it appear as self-defense or suicide. The former can be accomplished by planting recently-fired weapons near the body, the latter by fabricating evidence suggesting suicide.