Evidence
Evidence traces are little bits of evidence left behind.
しょうせき
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
部屋には犯罪の証跡はなかったが、警察は殺人事件ではないかと考えていた。
Although there was no evidence of crime in the room, the police determined that it was a murder.