A bestial grunt formed deep in his guts, like a trapped soul. ‘The girl, Marion, she’s deranged. She lunges at me, scratches my eyes so hard she leaves a piece of her fingernail in my cheek. I lash out. Instinct, you know? That’s when I realise I’d taken the knife off Laura. I’ve stabbed the girl in her hand. She’s seen me now. She knows who I am. I can’t go back inside. I have to finish her off.’

His face planted itself into the table and slid about helplessly on slobs of phlegm and snot and tears.

‘Interview terminated, 18.08,’ said Shep. He turned off the tape recorder, stood and inspected his stricken quarry.

‘Shit,’ said Mick, bolting to his feet and dashing to the door just ahead of Colin.

They reached the table just as Shep smashed Terry Foster’s face into the table. Mick and Colin swallowed Shep in a bear hug and led him out of there, rage convulsing his whole frame like bolts of lightning.

Chapter 41

Clapham Police Station, South London

Sunday, August 18, 1991; 19:00

Terry and Laura Foster were charged with the murder of Marion Ryan. Karen Foster was charged with perverting the course of justice. All three were denied bail.

Shep disappeared into his office for forty minutes, then summoned a briefing. As he outlined the case against the Fosters, he seemed flat, sickened, as if soiled by the words he was delivering.

‘Peter Ryan finally admitted today that both he and Karen Foster have a watertight alibi for the afternoon of Marion’s murder after all: from about four fifteen until six p.m. on July 1st, they were shagging in Bethan Trott’s room at the Pines care home. Of course neither of them wanted to admit it, right until the bitter end. It was only when we told Peter that we’d seized Karen’s pager and worked out all her movements from the transmitters on the day that he finally coughed. That’s not all he coughed to, but we’ll come to that later.

‘I have to be man enough at this point to say I became too focused on Karen Foster and it cost us valuable time and resources. McStay, Barratt, you were right. She didn’t murder Marion Ryan. But there was a reason why Karen kept popping up in the frame. Her own sister was trying to frame her.

‘A couple of days before the murder, Bethan Trott told Laura Foster that she was going to her mother’s after lunch that Monday, July 1st, and planned to be back by six p.m. Laura told Karen this news because Laura knew what Karen would do next: invite Peter to the room for sex that afternoon. Remember, Peter himself has said that, once he and Marion moved out of the halls in January, he and Karen preferred using Bethan’s room for their secret trysts as it was at the end of the corridor and out of sight. Karen’s room was next door to the matron’s.

‘Laura knew that Peter Ryan kept the keys to his flat in his briefcase, which was usually in the shed on the care home grounds. So, let me run through Laura Foster’s actions on the day.

‘She got home at three p.m. and told her dad Terry that Karen was being bullied at work by a woman who she wanted to “sort out”. When Terry refused to get involved, Laura threatened to tell her mum about something Terry had done to either her or one of her sisters. We might never get to the bottom of that, but it must have been pretty damning to give her that kind of leverage.

‘Terry agreed to drive Laura to the Pines in his work van, he thought to confront this woman who’d been bullying Karen. Before they left, Laura grabbed a black gym bag. When they reached the Pines, Laura told Terry to park up on the street outside and wait for her. Laura got out of the van and went inside the home. Ten to fifteen minutes later, she pulled up alongside Terry’s van in Karen’s car, wearing shades and a red top, told him to grab the gym bag and get in.

‘I will argue that Laura Foster went to the shed to retrieve the keys to Peter and Marion’s flat, then went to Karen’s room – remember, she had a key and her sister was with Peter in Bethan’s room – changed into her sister’s clothes, got hold of her sister’s car keys, car park pass and ATM card.

‘She used Karen’s pass to get out of the car park, pulled up next to Terry and told him that Karen wasn’t feeling very well. She said that the bully had already gone home and that Karen had asked them to go speak to her there. Terry got into the car with the gym bag.

‘Here’s where Laura decided to gamble. She parked just up the road from the Pines and used her sister’s bank card to withdraw ten pounds. She knew this would demolish both their alibis but had already decided that both Karen and Marion had to be taken out of the equation, and this was the only way.

‘Laura pulled up outside the Roundhouse pub. She and Terry unlocked both doors into the Ryan flat and waited for Marion, Terry behind a bedroom door, Laura up front on the landing. They must have both been wearing gloves.

‘When Terry heard Laura attack Marion he came out of his hiding place and realised Laura had stabbed her with the metal ruler he used for work. But she was still alive and she knew them both. Fearing a return to prison, he flipped and finished Marion off.

‘Laura had already packed a change of clothes for them both. She changed back into the black top she’d worn earlier, then drove them back to the clinic, dropped Terry off on the street and entered the car park. Right at the entrance, she spotted a woman emerging from reception who knew her and Karen. She stopped the car so that this woman couldn’t get a good look at her. It worked; that witness later assumed she’d seen Karen.

‘After Peter set off to clean the fish tanks, Laura got Karen out of Bethan’s room, greeted Bethan from the balcony and let her in. Laura told Bethan both she and Karen had been in her room since five. She left the gym bag in Bethan’s room because she knew she could bully and control Bethan. She had a two-hour window at that point to get the bank card, car keys, car park pass and shades back to Karen’s room, so that her sister wouldn’t suspect a thing.

‘Laura knew how crucial Bethan’s testimony would be. That’s why she put on such a show of grief when she heard the news about Marion in Bethan’s room. That’s why, the next day, she made sure Karen came with her when she retrieved the bag from Bethan’s room.

‘Laura must have been gutted when Glenn and his team ruled Karen out as a suspect. Five weeks later, when we started sniffing around, asking about Peter and Karen’s relationship, Laura saw her chance. She’d been controlling Bethan all along. Remember, she made Bethan provide the original alibi for both of them. It’s at this point it becomes clear now just how well Laura Foster has played us.

‘On the evening of the murder, Laura made sure she got Karen out of Bethan’s room before Bethan got back. By making sure Bethan didn’t see Karen, she could later prime Bethan about her “suspicions” about Karen’s involvement in the murder. Laura told Bethan about the times she’d caught Karen in her room eavesdropping on Peter and Marion. She told Bethan the hints Karen had dropped about what Peter was up to behind his wife’s back. She told Bethan about the time she saw Peter and Karen going into the shed together to have sex. She told Bethan she couldn’t shop her own sister to the police. Bethan had to pretend to be the one who’d seen and heard these things.

‘Remember the list?’

Shep produced a piece of paper from his inside pocket.

‘Bethan said she found this under her bed. It is a handwritten list of all the presents Peter bought Marion for her birthday in October last year, with the words “sick sick sick” scrawled at the bottom. Remember, this single sheet of paper set us on the trail of Karen and led to us finding out about the affair with Peter and Marion’s plans to move to Ireland. Well, guess what? I’ve had this examined. The list was written by Laura Foster.