Taxi driver Christopher Halliwell, who is beginning a life sentence for the murder of Sian O'Callaghan, has escaped justice over a second murder because of a police blunder.
Halliwell, 48, confessed to a senior detective to murdering Miss O'Callaghan and missing prostitute Rebecca Godden and even led officers to their bodies.
A High Court judge ruled the admissions the father-of-three made during a three-hour period on the day of his arrest were inadmissible because Detective Superintendent Steve Fulcher breached police guidelines governing the interviewing of suspects.
The detective, who was leading the hunt for Miss O'Callaghan, failed to caution Halliwell and denied him a solicitor. The ruling by Mrs Justice Cox meant that Wiltshire Police had no other evidence against Halliwell to link him to the Miss Godden's murder and the charge was withdrawn.
The father of Miss Godden hit out at police, saying they had "made massive mistakes".
"It seems to me: Come to Swindon, commit murder and you'll get away with it," John Godden told BBC News. "And that's the way I feel. I'll never put my trust in the police again. Why should we pay with this pain? For somebody else's mistakes? I want proper closure. I want closure. I want justice."
Wiltshire Police vowed to catch Miss Godden's killer and revealed Mr Fulcher has been suspended pending an investigation by the Independent Police Complaints Commission (IPCC) into allegations of "inappropriate contact with the media".
Miss O'Callaghan, 22, disappeared after leaving Swindon's Suju nightclub in the early hours of March 19 last year after a night out with friends. On the night she vanished, Halliwell had signed off from work but instead of going home he cruised the town's streets in his green Toyota Avensis taxi looking for a victim. As she made the short walk to the home she shared with boyfriend Kevin Reape, she fell into Halliwell's clutches by getting into his taxi.
Police believe Halliwell, who did not know her, took the young woman to the Savernake Forest where he murdered her. Miss O'Callaghan's semi-naked body was found down a steep bank and had suffered a brutal attack. A post-mortem examination found she died from the combined effects of two stab wounds to the head and neck, as well as compression to the neck.
Forensic examinations found Miss O'Callaghan's blood in the rear of Halliwell's car and police also had CCTV and automatic number plate recognition (ANPR) evidence to put him in the Old Town area when she vanished. Halliwell, of Asbury Avenue, Swindon, was jailed for life after pleading guilty at Bristol Crown Court to Miss O'Callaghan's murder.