The motive behind the murder of a dad-of-three is still a mystery one year on, detectives admitted today.

Officers investigating the death of James Tomlin scrutinised every aspect of his life but said they have yet to discover why someone had wanted to kill him.

On the first anniversary of Mr Tomlin's death in the arson attack on his home in Windhill, Shipley, police are renewing their appeal for clues to his killer.

The 36-year-old engineer died from smoke inhalation after an accelerant was poured through the front door of his house in Prospect Grove and set ablaze at 4.40am on Monday, August 15, 2005.

His partner of ten years, Sonia Chadwick, 27, was pregnant at the time and gave birth to a baby boy called Jamie in November.

She and their two children - Scott, now seven, and Dominic, now five - were rescued by firefighters. Mr Tomlin jumped from a back bedroom window as fire swept through his home but he was later pronounced dead at Bradford Royal Infirmary.

Detective Inspector Jeff Ashton, of West Yorkshire Police's Homi-cide and Major Enquiry Unit, said it was unclear why Mr Tomlin's home was targeted.

"We have uncovered nothing that would suggest why he was a target," he said. "There is nothing in James Tomlin's background to say that someone should wish to burn his home that we are aware of. There is a possibility that the wrong house was targeted, but it is a remote one. Until we catch the person we will not know why the family was targeted."

He said a post mortem had established that Mr Tomlin, who was sleeping in a different room to Sonia, died from smoke inhalation rather than as a result of the jump.

"James probably feared he was going to die so jumped from the window into the back garden," said Det Insp Ashton.

He said information had arrived very slowly at the start of the inquiry, but eventually Mr Tomlin's friends and associates, as well as other potential witnesses, came forward to help.

Det Insp Ashton said police believed people in the community still held clues vital to the inquiry.

"We believe that someone out there has answers to our questions," he said. "Maybe the person concerned has said something to someone. It may be they are close to the person responsible, but they can come forward in confidence. There are ways we can deal with people to keep their evidence in confidence.

"We want to catch the person responsible to help Sonia and her family to move forward.

"Considering these very difficult times, Sonia is bearing up. But the children have lost their dad and the baby born afterwards will never see his father. It is a tragic situation for them all."

Anyone with any information should contact Keighley Police on (01535) 617167 or Crimestopp-ers, anonymously, on 0800 555 111.

e-mail: jonathan.walton @bradford.newsquest.co.uk