‘Not necessarily. The e-mail was on a timed send. But there’s more.’ Brauner, carefully using a single latex-gloved finger, selected ‘hide application’ and the laptop’s desktop was exposed. Brauner clicked on a sequence of folders. They were all empty.

‘This is weird,’ said Brauner. ‘What kind of serial killer goes in and wipes all his victim’s computer records?’

‘Can I take the laptop in and let Technical Section have a look at it?’

‘No, not yet. We’ve dusted for prints but I want to open this up. Computer keyboards are as much cracks as buttons … all kinds of stuff gets trapped under the keys. With a bit of luck we might get a hair or some epithelials from our killer.’

‘I doubt it very much,’ said Fabel, dispiritedly. ‘This guy doesn’t make mistakes. Despite the messiness of the method of killing, it’s almost as if he kills in a forensic cleanroom. He leaves nothing of himself behind.’

‘It’s still worth a try,’ said Brauner, trying, but failing, to sound encouraging. ‘Maybe we’ll get lucky.’

‘I doubt it. Can I tell Möller he can come in now?’

Brauner smiled. ‘I suppose so.’

On the way out to the corridor, Fabel checked on Anna Wolff, who was looking yellow-pale under her spiky black hair and the trademark mascara and flame-red lipstick.

‘I’m okay, Chef … Sorry. It just got to me this time …’

Fabel smiled reassuringly, ‘There’s no need to apologise, Anna, it happens to us all. Anyway, your penance will be bad enough: Brauner and the Tatort team are never going to let you live it down.’

Werner tapped Fabel on the shoulder. ‘You’re not going to believe this, Jan … we’ve got a time of arrival and a witness.’

‘Do we have a description?’

‘Not a great one, but yes we do.’

Fabel made an impatient face.

‘There’s a girl who lives on the floor below,’ Werner continued. ‘She’s about thirty and works for an advertising agency or something equally worthwhile and meaningful. Anyway, she’s got this new boyfriend. They had been to a health club for a workout and got back here before nine p.m. I get the impression the boyfriend was planning on another workout with her, the horizontal kind, but he’s not been around long enough to have been invited up. Anyway, he parked across the street about eight-thirty. They were sitting in his car with the engine off – he was obviously doing his best to persuade her to let him come up. It was then that they saw this guy arrive on foot. They didn’t notice a car, so if he had one he must have parked it some way away. They paid attention to this guy because, just before he pressed the entry button for one of the apartments, he made sure he had a good long look up and down the street. She said he even checked out the lobby through the glass doors.’

‘So she got a good look at him?’