Police have released these photos of a hammer which they believe is the weapon used to kill Valerie Graves in Bosham.
It was found in Bosham by the search team working on the murder inquiry.
Miss Graves was discovered dead in a ground-floor bedroom on the morning of Monday 30 December at the house in Smugglers Lane she was looking after with three other members of her family, while the owners were away.
She died from significant head and facial injuries.
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The 22 year old man is seriously injured in hospital. Police believe a baseball bat and iron bar may have been used in the attack