The gun had been given to the old DI by the murderer, knowing that he’d be implicated eventually as the murders were investigated. Corstorphine experienced the same feeling he had had at the first murder scene; that he was being played. Each death was meticulously and cold-bloodedly planned and executed, each murder following the next like clockwork. Brian would have had the chance of fighting this in court, of proclaiming his innocence or risk being convicted and sent to prison. The old DI must have known he’d be found guilty of abetting in the unlawful burial of the children, at the very least, and he’d have known what to expect as a copper behind bars – especially if any connection to child abuse was mentioned. So, Brian had had Hobson’s choice. No bloody choice at all. The murderer might just as well have held the gun to the old DI’s head and pulled the trigger. He called Frankie on the radio, hoping she was still at his house.

“Frankie, Corstorphine here. Can you ask Molly if Brian had delivery of a package recently, one that may have contained the gun? There’s an inscription on the stock, looks like it’s our same murderer who sent it to him. Over.”

Frankie’s response came back, requesting time to talk with Molly. He added the photos he’d taken with his mobile to the crazy board and included one of the gun stock whilst he waited.

“Molly said he had a shoebox-sized parcel delivered about six months ago. Says she only remembers because he was evasive about what it contained. He’d said it was a pair of shoes, but he hadn’t shown them to her until a few days afterwards which she’d found odd. Not as odd as him buying shoes from France, though.”

“Why did she think they came from France?”

“The box had French writing on it.”

“Did she keep the box, or the stamp? Anything that we can use as a lead?”

“No, sir. I asked her that. It went straight into the recycling. Sorry.”

Corstorphine sighed, another possible lead closed down. “OK, Frankie. How’s Molly bearing up?”

“You’re not flavour of the month, sir. She seems to hold you responsible for his suicide, says you pushed him to it. There’s family turned up now, sir. I’ll just make sure they’re all OK then head back. Over.”