Stephen Cookson's head washed up on Rottnest. Credit:Channel Ten News. He said the forensic search had ruined the flooring, the furniture, the carpets, and just about all the fixtures and fittings. He has since spent tens of thousands of dollars repairing the apartment but the police earlier this year refused him any compensation because the damage was "not malicious". "The police left the place in a worse state than the murderer who cut up his victim's body on the floor of the apartment," Mr Coward said. "The officers involved in the investigation have apologised and said that the apartment should never have been left in such a state, but the police's legal services department won't give me a cent."

Police searched a Golden Bay property as part of the investigation into Stephen Cookson's death. In 2012 Mr Coward's tenant in the Hay Street apartment sublet the unit to Cookson and then moved out telling him he would have to deal directly with Cookson in future. That would prove difficult. Cookson was a violent drug trafficker and wannabe horse racing identity who refused to pay rent and threatened Mr Coward when he asked for his money. Angle grinder mark in the bathroom floor where Aaron Carlino cut up the body of Stephen Cookson. Credit:Troy Coward "He tried standing over me. He phoned me up when he was off his head and threatened to kill me. But I didn't back down. I just kept telling him I wanted him out of the unit," Mr Coward said.

Eventually Cookson agreed to move out and told Mr Coward he would be gone by December 16, 2012. Filthy cleaning cloths from Troy Coward's attempt to clean unit after police forensic investigation Credit:Troy Coward Cookson lived in the apartment with Aaron Carlino but their relationship ended in the kind of nightmarish violence usually seen in horror movies. On December 15 Carlino used a rifle to shoot 56-year-old Cookson. He spent the next day cutting up the body and putting it into bags. Filthy dishwasher and walls after police forensic investigation in Troy Coward's apartment Credit:Troy Coward

In the middle of this grisly operation Mr Coward turned up at the apartment hoping the pair had moved out. But Carlino would not let him in and they had a shouted conversation through the closed door. "I asked him where Cookson was and he said he hadn't seen him for weeks. He said the unit was dirty and he was tidying up and told me to come back a few hours later," he said. "I guess I am lucky I didn't have a spare set of keys or I would have walked into the middle of a blood bath. God knows what might have happened then." Carlino used an angle grinder and a kitchen knife to cut up the body before he and his accomplices buried the body parts at a property in Golden Bay. Later they dug up the body parts and put them onto a boat and set out in the direction of Rottnest throwing the remains overboard in bags weighted with bricks.

But something went wrong and Cookson's head washed up on beach at Porpoise Bay on Rottnest. On January 6, 2013, it was found by an 11-year-old girl. By this time Mr Coward had managed to get Aaron Carlino out of the Hay Street apartment and he moved in to clean it up, intending to live there – not knowing that he was cleaning up a murder scene. "It just looked like it was dirty. Looking back there were no obvious signs of blood or any sign of violence although later I did notice that the carpets had been cleaned with some form of chemical," he said. Five days after Cookson's head was identified. WA Police had worked out who he was and his last address. The drove to the apartment in Hay Street and told Mr Coward he had to leave the apartment while forensic officers went through it. "They let me take my wallet and my car keys and that was it. I ended up sleeping on the floor at my office."

Looking back he realised that there was a time when the police suspected he may have been the killer. "I know how it looked. Cookson owed me money. I got the keys from a murder scene. I cleaned up the murder scene," Mr Coward said. "I think that because I was the number one suspect for a while that the police were just careless about how they treated the apartment because they thought I was going to end up in prison." The police even raided a second property owned by Mr Coward. "They went to the Lesmurdie house and took the fridge, the bed, washing machine, dryer and the microwave, and I never got those back either," he said.

But the police soon began to focus on Aaron Carlino as the likely murderer and eventually he was arrested and charged with killing Cookson. Major Crime detectives then met Mr Coward at the apartment to let him have the keys back. "I was gobsmacked with the state of the place. It was destroyed," he said. The apartment's wooden floors were all scratched and stained with chemicals used by the forensic officers. All the carpets were covered in various forensic inks and dusts. Luminol had highlighted blood spatter on the ceiling. Furniture was scratched. Skirting boards had been pulled off and mirrors ripped off walls and broken. Some plumbing pipes had been removed as had an air conditioning vent.

The officers pointed out two bits of damage they were not responsible for. One was a hole in a kitchen tile caused by one of the two bullets Carlino shot into Cookson. And the other was a mark on a bathroom tile caused by the angle grinder Carlino had used to cut up Cookson's body. The officers were apologetic about the damage cause by the forensic investigation. "They told me they needed quotes for the damage and they were happy to sign off on it," Mr Coward said. But WA Police's legal services department took a different view. They wrote to Mr Coward's lawyers saying there would be no compensation.

Their letter said that the confiscation of the unit and damage caused was the result of a lawfully justified investigation and that because the damage caused was not the result of malice the police were not financially responsible for the damage. "An action in tort does not lie against a member of the Police Force for anything that member has done, without corruption of malice, while performing the functions of a member of the police," the letter read. "This is crazy," Mr Coward said. "There needs to be some legislation which protects someone like me who is expected to clean, repair and pay for damage caused by a police forensic investigation. "I have been fighting for justice in this case for three years now – and I am still waiting."

WA Police issued the following statement. "WA Police received a claim for compensation from solicitors acting on behalf of Mr Coward. WA Police sought advice and a letter has been sent to the interested parties outlining the reasons for the decision. There has been no further correspondence from either Mr Coward or his legal counsel," it said. Aaron Carlino is serving life imprisonment, with a minimum term of 23 years, for the murder of Stephen Cookson.