Sam Brewster Detective Inspector Sam Brewster ' s investigative career with the Weatherfield CID brought him to Coronation Street on three occasions during the 1970s . In July 1973 , then a Detective Sergeant , Brewster headed up the investigation into Bet Lynch ' s mugging . Bet couldn ' t identify her attacker , but provided Brewster with his first lead when she told him that her £75 cut of a syndicate pools win was in her stolen handbag . Brewster suspected Stan Ogden , a fellow syndicate member . Under questioning , Stan lied about his movements before meeting Hilda at Jackson ' s Chip Shop , their destination immediately before they came back to the street and found Bet . With the finger of suspicion pointed at him , Stan - away from Hilda ' s ears - admitted to Brewster that he had been carrying Clara Regan ' s shopping home for her to 19 Inkerman Street during the missing fifteen minutes . Once Mrs . Regan confirmed Stan ' s alibi , Brewster let Stan know - in front of Hilda - that he was in the clear and exactly who he had to thank . Another suspect was Norman Leach , who had recently threatened Bet , although Bet refused to tell the police why . Brewster told Bet that he couldn ' t proceed without full disclosure , but in any case Leach ' s mother gave him a complete alibi for the evening in question . The police were left with no leads until Bet ' s handbag surfaced , having been tossed over a wall in the yards . The bag contained the £75 and Leach ' s fingerprints . The CID had a good case against Leach , but still lacked a motive . This was provided by Alf Roberts , who fearful that Leach was going to get away with it , went to the police station to tell them what Bet was holding back for his protection : Leach had blackmailed Alf for £200 in exchange for keeping quiet after Alf " hit " his mother with his car ( which was stationary at the time ) . As Mayor - elect , Alf couldn ' t risk a fuss so paid Leach for his silence . However , Bet , who had been with Alf in the car , forced Leach to return the cheque to Alf , correctly assuming that he had a criminal record and had more to lose from the situation than Alf . Brewster admitted to Alf that they had Leach in a cell and using the threat of charging him with blackmail , he invited Leach to plead guilty to assault . Brewster meant the threat as a bluff ; as he told Alf , the courts would see the demand for money as an offer to settle out of court . Leach refused to play ball , but upon further consideration , he changed his plea to guilty . Brewster next visited Coronation Street just after a robbery at Baldwin ' s Casuals in which wages clerk Ernest Bishop had taken a fatal shotgun blast . Now an inspector , Brewster took over factory owner Mike Baldwin ' s questioning from Det Sgt Thornton , going over the moment leading up to the gun being fired and getting descriptions of the gunmen while they were fresh in his mind . The men grew impatient with each other as Mike had only caught a brief glimpse of the men and was still in shock , while Brewster had to press him on the finer details . Afterwards , he arranged for Thornton to use Elsie Howard ' s office to interview the factory girls . As the wages snatch had taken place on a week when bonuses were being paid , Brewster suspected that the culprits had inside knowledge , but leaned towards the information being given out innocently rather than an inside man being more directly involved . Mike was then taken down to the station to look at mugshots . Using the information provided , the police apprehended the shooters , Ed " Tommo " Jackson and Dave Lester within days , and they were later found guilty of first - degree murder . Brewster ' s final case in Coronation Street was the search for missing mother and daughter Deirdre and Tracy in the wake of a lorry overturning in Rosamund Street and spilling its load of timber into the front of the Rovers . At first , Tracy was thought to be under the wreckage , but a search underneath only turned up Tracy ' s doll . When the fireman went to tell Deirdre , she thought they were going to announce that they ' d found Tracy dead , and slipped away from 3 Coronation Street with suicidal thoughts . Brewster was intrigued when Emily Bishop outlined the difficult few years Deirdre had been through , which included an assault in 1977 and a marriage breakdown several months earlier . Considering the possibility that Deirdre had killed Tracy herself , he questioned Emily , Annie Walker and Bet Lynch on Deirdre ' s state of mind before the crash . Annie and Bet confirmed that neither of them had actually seen Tracy outside the pub . Ena Sharples provided Brewster with a lead when she identified the doll as a gift to Tracy from Sally Norton , whose own baby had been put up for adoption . Emily got Sally ' s address from the hospital , and police found Tracy with Sally , having been snatched from outside the Rovers mere moments before the crash . Deirdre was located shortly afterwards at the canal side by WPC Harris . To stop her jumping into the water , Len Fairclough went back to get Tracy to prove that she was alive .