Jo let out a long breath. ‘I don’t know. It would be different, obviously. I mean, I wouldn’t be getting calls at one in the morning because some asshole has blown a hole in his wife’s chest, but I imagine that buzz you get on cases – you would miss it sometimes.’ She watched as Barnes made notes. ‘Although, I don’t know if “buzz” is the right word exactly. I’ve been a cop for over eighteen years, and at some point that buzz became more like a …’ She sighed, searching for the word.

‘A debt?’

Jo glanced at Dr Barnes.

‘Exactly,’ she said. ‘Exactly.’

Her eyes stayed on the psychologist, trying to read her, finding something in Barnes’s choice of phrase that she identified with instantly. A debt. That was exactly what it was.

‘But for now,’ Barnes said, moving on, ‘you’re still a cop?’

‘I’m still a cop, yeah.’

‘Did you always want to work homicides?’

‘Always,’ she said. ‘I never wanted to do anything else. I guess, to start with, I wanted to be a cop because I was an obstinate jerk and needed to prove that I was just as capable as any man. It was hard, though. When I graduated from the academy in ’74, it was still compulsory for female deputies to wear heels, skirts and lipstick.’ She flashed Barnes a humourless smile and, for a second, the psychologist broke from her professional sobriety and rolled her eyes. ‘That rule got tossed in the trash soon after – but there was plenty more garbage to go around. You remember the Night Stalker?’

‘Sure. It’s pretty hard to forget a man like Richard Ramirez.’

‘You probably know all this already then, or you’ve heard, but while he was busy putting the city on its knees in ’85, the push to track him down turned into one of the biggest manhunts in the entire history of US law enforcement. Plus, we were in the middle of a crack epidemic too. What I’m saying is, I’d been a detective for seven years by that time, and I alone was catching at least one new homicide every week. So, after seven years, I had a ton of experience. But do you know when I got asked to join the Night Stalker task force?’

Dr Barnes shook her head.

‘Never,’ Jo said. ‘I did zero hours on that. They didn’t trust me.’

‘Because you were a woman?’