suspicion will raise bogies; once you suspect something, everything else will look suspicious; jumping at shadows
彼は疑心暗鬼になっていた。
He was jumping at shadows.
盗難事件後、社内は疑心暗鬼に陥った。
After the theft, the office fell into a state of paranoia.
彼は疑心暗鬼の状態で、誰も信じられなかった。
In his state of paranoia, he couldn't trust anyone.