DETECTIVES hunting the killers of a pensioner who tried to stop them stealing his car have admitted there has been a poor response to their appeals.

The revelation came as officers investigating the killing of James Simpson, 76, revealed they will today make a further attempt to speak to his shocked widow.

Minnie Simpson, 72, who is thought to hold the key to the inquiry, has been suffering from flashbacks and has not been able to talk for long about Tuesday's horrific incident.

She had witnessed her husband being run over by thieves taking his black LandRover Discovery from outside their home in Ashgill, near Larkhall, Lanarkshire.

On Friday, the couple's son Jamie, 39, made an emotional appeal for whoever committed the crime to come forward.

A Strathclyde Police spokesman said: "While the response from the public in expressing their sadness and shock at the death of Mr Simpson has been significant, unfortunately, in terms of the murder investigation, the response has been poor and our appeal has not generated as much information as we had hoped for."

At a press conference in Larkhall police station, Minnie sat beside her son but was too devastated to say anything. Police say they hope to speak to her "at length" in the next few days.

Jamie Simpson, a civil servant, had said his mother "no longer wants to live" after seeing her husband killed in the street.

He described how he saw his father "lying on a cold table with blood on his face" after thieves broke into his home and stole car keys before running Mr Simpson over as he tried to stop them taking the vehicle. Police say they believe the killers, who later abandoned the car three miles away in Crossford, are from the local community.

Mr Simpson said: "These individuals thought it was their right to break into my parents' home, take the car keys and steal the car. And when my father ran to defend his property he had worked hard to get, these individuals also felt it was their right to run over my father, leaving my dad abandoned and dying on the kerbside."

One suspect is described as having short, dark hair and wearing dark clothes. Police are also searching for a white man in his thirties who they say was behind the wheel of the car when it hit Mr Simpson.

Floral tributes have been left to James, who was known as Jimmy, outside the Simpson house, where he had lived for 45 years.

The vehicle is now undergoing forensic tests in a bid to trace those responsible for the killing.

Police are understood to be focusing their inquiries on a number of local crime groups.

One theory under consideration is that the car, which retails at around £35,000, was stolen to order.

As police investigated, machinery from South Lanarkshire Council was brought in to empty drains in the street while officers raked through the findings.

In a similar case around 10 miles away, a teacher was injured two months ago after allegedly disturbing a car thief.

Ian Howson, 57, was allegedly attacked outside his home in Lefroy Street, Coatbridge.

The former head of Caldervale High, Airdrie, now teaching at St Ambrose High in Coatbridge, was attacked on October 3.

Liam McGowan, 19, was later arrested and charged with attempted murder, theft from a motor vehicle, vandalism and housebreaking with intent to steal.