Originally Posted by
Enigma368
Can TSA search personal items that pose no security risk?
Yes.
Originally Posted by
Enigma368
Do they also have a duty to investigate potentially suspicious items not related to flight/airport security?
Except FAM, TSA are not LEOs. So they do not exactly have any investigative authority. However, when it looks suspicious, they can refer to proper authority.
The real question is - would you rather talk to a TSO or an actual LEO, either local or federal, after detention?