Randle is shown on CCTV footage at BudgensWILLIAMS VERDICT: A MIXTURE of old fashioned police graft and the accuracy of forensic science helped nail Randle Williams, according to the man in charge of the £1m murder investigation.

DI Graham Hatswell said the amount of forensic evidence against Williams was crucial in bringing the wife-killer to justice.

He said without the wealth of forensic data the case would never have got off the ground.

Meanwhile officers resorted to what he termed "good old fashioned police work" painstakingly tracking down the origin of clothing found at Biss Bottom and scanning hours of CCTV video tapes.

"We have never had this much forensic evidence in an inquiry. I knew we had to be as conclusive as we could," said DI Hatswell.

"That meant finding more finance than normal.

"We really pulled out the stops. We had to. I knew he would question everything and anything. Without forensic science this investigation would not have been happening."

DNA profiling animal hair and river water analysis and footwear sampling were among the techniques used to link most of the clothes to Williams and the murder scene at Greenland Mills, creating an almost impossible set of circumstances for him to explain away.

CCTV evidence from stores like Tesco and Budgens proved vital as it disproved Williams' account of his movements on the night of the crime.

A diesel receipt found on the banks of the River Avon was another nail in Williams' coffin as police were able to prove he was in Warminster on the day after Natalie's killing.

DI Hatswell said releasing their prime suspect after the maximum 96 hours of questioning was a risk worth taking. Officers from the National Crime Squad and Dorset police were drafted in to follow the 43-year-old and sites at Knook Camp, Chitterne and Biss Bottom were searched.

"We knew we had the right man and we had to let him go. We wanted to understand how he thought and try to predict what he may or may not do," he said.

Deputy investigator Det Sgt Andy Cross made a TV appeal for washing powder and refuse sacks the team knew Williams had bought in Warminster forcing Williams to make his move and lead them to the second crime scene. The detectives found a wealth of evidence proving Williams had tried to create back-up evidence for his tale.

A note was found in a bin at Greenland Mills from Williams to his wife claiming he was out searching for her timed at 12.20am. An early morning message was also left on the couple's answerphone from Williams.