The murder of a scientist who was gunned down by a hitman on her doorstep is back in the spotlight after 27 years as detectives renew appeals for information.

Karen Reed, 33, was shot five times after answering the door to a man disguised as a pizza delivery driver on Saturday April 30 1994.

Investigators believe the professional hit in Woking, Surrey, was a case of mistaken identity, and that the intended target may have been Ms Reed’s sister, Alison Pointing, whose husband was jailed for murdering a former Chechnyan prime minister and his brother.

An artist's impression of the suspected hitman
An artist’s impression of the suspected hitman (Surrey Police/PA)

Appeals for information about the killer were renewed on Wednesday and pictures released to the media for the first time.

The case was also featured on BBC’s Crimewatch Live.

Deputy senior investigating officer Detective Inspector Gareth Hicks, of Surrey Police, said: “People out there know who killed Karen Reed.

“Whether it’s the individual who pulled the trigger, or those who were assigned to arrange this contract killing, it’s time for them to come forward.

“Karen was an innocent young woman who was loved by those who knew her, worked hard and had no previous involvement in criminal activity.

“She worked in Addlestone as a geophysicist and was enjoying a glass of wine with a friend when she was brutally murdered.

The gun and silencer found in the suspected killer's car
The gun and silencer found in the suspected killer’s car (Surrey Police/PA)

“We strongly believe that this murder was a case of mistaken identity and a contract killing which went wrong.

“Those who are out there and know what happened may feel more comfortable in coming forward with information due to certain loyalties and relationships breaking down over time. It’s time for these people to do the right thing and help us.”

On the evening Ms Reed died, she was at her home in Willow Way on the Barnsbury Estate in Woking when she answered the door at around 9.15pm.

The bogus delivery driver, who was tall, dark-haired, wearing glasses and holding a blue and white pizza box, asked her to confirm the address before shooting her at close range five times.

Despite a murder investigation that saw detectives take 1,700 statements, the hitman has never been identified.

It is believed the killer had made a bungled first attempt two weeks earlier, but ran off when his red Vauxhall Cavalier attracted the attention of police.

The Delsey bag found in the suspected killer's car
The Delsey bag found in the suspected killer’s car (Surrey Police/PA)

When officers searched the car, they found a gun fitted with a silencer, along with a map to the Barnsbury Estate, as well as a commando knife. There was also a black Delsey Bag plus a rare Olney blue tartan cap.

Anyone with information can contact the Surrey Police Operation Lilac team on 01483 639969 or online via webchat at surrey.police.uk.

To remain anonymous contact Crimestoppers on 0800 555 111.

A reward of up to £10,000 is on offer for information which leads to the arrest and conviction of those linked to Ms Reed’s murder.