Complex sentence: After a lengthy investigation, police were given a description of the man who purchased the hammer from a local shopkeeper, which were similar to the description that eyewitnesses provided of a man last seen in the company of Balchin on the night of her murder.
Split into simpler sentences: After a lengthy investigation, police were given a description of the man who purchased the hammer from a local shopkeeper. Comparing the description with eyewitness accounts of a man last seen in the company of Balchin on the night of her murder.