Expression: Go over with a fine-tooth comb
to examine very thoroughly
If you go over something with a fine-tooth comb, you examine it in detail. If you are talking about a room, or a place, going over it with a fine tooth comb means searching it thoroughly.
EXAMPLES USING THIS EXPRESSION:
“They went through the house with a fine-tooth comb.”
“It’s my fault for not going over it with a fine-tooth comb.”