blameless
Not responsible for doing anything wrong in a situation.
Blameless means free from fault or guilt, not deserving criticism or punishment for something that happened. When you're blameless in a situation, you haven't done anything wrong, even if something bad occurred.
Imagine your little brother knocks over a glass of milk while you're sitting across the table reading. You're completely blameless because you had nothing to do with the spill. Or suppose two students get into an argument during recess, and a teacher questions everyone nearby. The kids who were playing elsewhere are blameless because they weren't involved at all.
The word doesn't mean you're perfect in every way. It means that in this particular situation, you bear no responsibility for what went wrong. A driver in a car accident might be blameless if another driver ran a red light and caused the crash.
Being blameless is different from being innocent after you've been accused. Someone who is blameless simply hasn't done anything wrong to begin with. When investigators determine that someone is blameless, they're confirming that person shouldn't face any consequences because they weren't at fault.