How to use "clues" in a sentence

Sentences

The police had no other clues to help them find the killer

The Ripper murders were the first of a new kind of crime: serial killings, savage, without an obvious motive, no clues, and very difficult to solve.

Sala watched them, searching their faces for clues

There were no more intriguing tidbits like Project Pandora, no more clues or leads.