Christopher Dooley planted home-made NAIL-BOMB in neighbour's garden Christopher Dooley, 40, became obsessed with Joanne Dixon, 34, after his wife died He made a T-shirt with her face on it and put a tracking app on her mobile Dooley then placed a homemade nail-bomb on her front doorstep Mrs Dixon later found her three-year-old son Levigh playing with it She called the police who carried out a controlled explosion of the bomb Dooley was jailed for three and a half years at Preston Crown Court A widower obsessed with his next-door neighbour has been jailed for three and a half years after planting a live nail-bomb in her garden. Father-of-eight Christopher Dooley, 40, began pestering Joanne Dixon, 34, after his wife died aged just 31 from deep vein thrombosis. A court heard Dooley made a T-shirt with a photo of Mrs Dixon printed on it and gave her a Samsung phone after secretly downloading an app on to it to track her whereabouts. He then researched gunpowder on the internet before planted his homemade device outside Mrs Dixon's front door after which he texted her saying: 'Just had a walk round to yours. Shame that. Behind bars: Christopher Dooley, 40, pictured left, has been jailed for three and a half years after leaving a homemade nail-bomb on the front doorstep of his neighbour Joanne Dixon, 34. She discovered her three-year-old son Levigh, pictured together right, playing with the device and called police Mrs Dixon's three-year-old son Levigh was playing with his two older sisters when he spotted the plastic tube, which contained a small bag of nails and gunpowder with a wick coming out, and picked it up. He then unwittingly began playing with it until his mother saw him and took the device away. As she picked it up she saw black powder pour out and called police. Bomb squad officers were called to the house to make the device safe. Police later raided Dooley's home in Preston, Lancashire, and found electrical equipment which had been used to make the bomb plus. They also discovered a towel with black powder residue in his kitchen bin. An expert described it as a 'viable, explosive device'. Dooley sobbed as he was jailed for three and a half years at Preston Crown Court after admitting charges under the Explosives Act of making and possessing an explosive. But Mrs Dixon, also a mother-of-eight, criticised the 'mild' sentence. She said: 'He could have killed us all and the jail term seems very mild, given the effect what he did has had on my kids. Dangerous: Mrs Dixon called police who sent an Army bomb disposal unit to her home. The device was destroyed in a controlled explosion It was the hottest day of the year and we have been told if the sun had hit it the heat may have been enough on its own to set it off. We were told it was strong enough to have killed Levigh and maim any adult who was in a certain distance. She added: 'I took the package off Levigh and I didn't know what it was at first, until the powder came out. Then we noticed the tiny nails attached to it. The police operator sounded shocked - they said: "Put it outside and do it now, now, now." My children were terrified when they realised what they had been playing with. This could've injured at least 10 people and would have most definitely killed my Levigh. This man was definitely obsessed with me but I just saw him as a friend and nothing else. 'It's disgusting what he has put me in my family through and I wish he had got longer in prison.' At an earlier hearing, prosecutor Amanda Johnson said the pair had lived around the corner from each other for ten years but Dooley tried to get closer to her after his wife Christine, a school governor, died in 2010. Mrs Dixon, pictured, criticised the sentence handed to Dooley for being too short 'She acted as a shoulder to cry on but began to become concerned that he was developing some sort of obsession with her,' said Miss Johnson. He bought her expensive gifts like a mobile phone, he had a T-shirt printed with her photo on and put an app on her phone to track her whereabouts. On the morning of July 13, Joanne saw her son in the front garden playing with what appeared to be a black plastic tube that had a lid. It had a wick coming out and a small bag containing nails. She opened the lid and black powder poured out. She was concerned it was a nail bomb. An Explosive Ordnance Disposal team were called to examine the device and ensure it was safe. They carried out a controlled explosion of the device and no one was injured. Dooley was identified as the culprit after another of Mrs Dixon's daughters said they had seen him handling the black powder the previous day. Mrs Dixon and her new boyfriend confronted Dooley but he denied any involvement, claiming he had been in all night caring for his children. Dooley's cleaner later said she had seen fireworks within the kitchen and him pouring powder out of them into a cup. His fingerprints were on the tape of the plastic bag of nails taped to the device. Dooley claimed he had been in a relationship with Mrs Dixon for five months and was 'pestering' her to keep it going - only to find out she had a new boyfriend. Miss Johnson said: 'He accepted he had sent a text and agreed he had been pouring gunpowder into cups and had thrown remnants into the bin. He agreed that he had been researching matters on gunpowder on the internet three days earlier. She added that the fuse end had been charred as if an attempt had been made to ignite it. In mitigation, defence counsel Peter Turner said: 'These two people have had a relationship. He is not an unintelligent man but he has collapsed inwardly since his wife's death. He has not been able to go into the living room where she died. Blown to pieces: Components of the bomb after it was destroyed in a controlled explosion He witnessed that, he tried his best to care for her and he has never recovered from it. He is not able to recall lighting the device that he took to her home. Passing sentence, Judge Anthony Russell QC told Dooley: 'It was your connection with that lady, described as an obsession, that you made that nail bomb from the powder of fireworks and nails placed in plastic bags. Nails would have been propelled around, potentially causing serious injury and acting like shrapnel. It was found by children who had played with it before their mother discovered it. It may have been you were suffering from depression. The circumstances which your wife died are very sad indeed but they cannot excuse your actions. The fact that the device contained nails, was placed in the garden of the dwelling and found by children render the case as serious. After the case, Det Sgt Martin Pearson said: 'Clearly this was distressing for the victim, whose child found the device. Fortunately no one was hurt in the process. Lethal: Mrs Dixon said bomb disposal officers believe the sun could have set the bomb off