A man 'in women's clothes' and a bloodied wrench may hold the key to a 30-year-old murder probe, say police.
Martin Broom, 29, was killed in a hammer attack in Boreham near Chelmsford in 1989. No-one has ever been charged with his murder.
Police have released four key leads they want the public's help with as they seek Mr Broom's killer.
His family had "spent 30 years waiting for justice", said a spokesman, urging witnesses "to do the right thing".
Mr Broom was beaten to death at his home in Sussex Close on 22 July. The murder weapon, a small hammer, was found at the scene and a bloodstained wrench was also recovered.
There was no sign of forced entry and nothing was stolen, though the house appeared to have been searched.
Essex Police made several arrests but now want information linked to four strands.
- A red E-reg Vauxhall Astra was seen visiting regularly - the passengers were a blonde woman and a slim white man with fair hair and silver wraparound glasses
- A woman was seen getting out of a green/brown estate car at the house, but reports to police suggest it may have been a man in women's clothing. The person was described as aged 18-25 with "dark, feathery-cut hair"
- A bloodstained Stillson brand wrench, made in India, was found nearby - its owner was never identified
- Guests at a party in the area on the night Mr Broom was killed may have seen something unusual without realising its significance
Mr Broom's childhood friend Ian Lawrence said he would not be forgotten.
"Every year I think of him. I keep hoping someone will be caught, with advances in forensic techniques," he said.
"It makes me very sad. I've got married, had children, a family, and all that was taken away from him at 29."
A police spokesman said all new leads would be followed up.
"Three decades is a long time, during which loyalties change and people, who felt unable to come forward to us before, may feel now is the time to do the right thing," she added.