‘Then comes the explanation about what is happening and the rules to his sick question game. And with that we’ve got two new elements. First, doubt – because that’s when the mind starts going, “Is this for real? Am I dreaming this crap or what?” Second, an introduction to fear – because if this turns out to be real, then your best friend’s life . . . your wife’s life . . . is in your hands.’

Captain Blake crossed one leg over the other, the look in her eyes clearly indicating that things were just starting to make sense in her head.

‘So even before the question game starts, Captain,’ Hunter carried on, ‘in the space of two minutes or less, the witnesses’ brains have been bombarded by a shower of unbalancing elements – surprise, confusion, shock, doubt, and just enough fear to make them question everything. In the midst of all that, while the witnesses are still trying to figure out if they’re dreaming or not, if they’ve been caught in the middle of an elaborate prank or not, the killer hits them with his first question. An extremely easy question. Something he knows they’ll get right.’

Hunter indicated both questions on the board: ‘How many Facebook friends do you have?’; ‘Where was Cassandra born?’

‘That first question is a very clever question because it essentially does two things, Captain. One: It brings back a combination of “confusion” and “doubt”, because right then the witnesses can’t believe that this game can be real. Not with such easy questions. So they start believing that whatever this is, it must be a prank. And, two: It gives them a false sense of security, because if these are the types of question they’re going to be asked,’ Hunter made a ‘c’mon’ gesture with both of his hands, ‘then bring on this stupid game.’ This time, Hunter paused for effect. ‘And that false sense of security expands inside the witnesses because after all, they’re now fifty percent there. Remember the rules of the game? Two correct answers and the game is over. Your friend is free. Your wife is free. And here’s where this killer shows how clever he really is.’

Captain Blake pushed a lock of hair away from her face.

‘By now, he’s already unbalanced their thought processes without them realizing it and he’s given them a false sense of security, but his trump card is still to come.’

‘Trump card?’ the captain asked.

‘He’s never told them what the consequence to a wrong answer is,’ Garcia jumped in.

Hunter pointed at his partner as if he’d given the answer to the ultimate question.

‘They have no real idea of what will happen if they get a question wrong, Captain,’ Hunter said. ‘And after that first easy question, the game is now sounding silly. So the killer hits them with his second question. The question.’ Once again, Hunter indicated the questions on the board. ‘Something he researched. Something he’d found out that they should get wrong, but it’s still only a “should”.’

‘What do you mean – only a “should”?’

‘Think about it, Captain. This killer didn’t just decide to go on a killing spree from night to day. He’s been planning his murders for some time. And he’s very, very patient, because his is a lengthy process. He starts by choosing the victim, someone he taunts with messages, and, from what we gathered, he does it for months. Then he chooses the person to play his question game. Someone close to the victim. Finally, he researches what question to ask them, because the trick is – the question needs to sound easy, but be difficult.’

Captain Blake nodded. ‘OK.’

‘If we are right about this killer finding out which question to ask by scrutinizing social media websites –’ Hunter continued, ‘and I think we are – those posts have been up for months. But even if we’re wrong about the social-media websites, how long do you think it’s been between him finding out which question to ask and the murder itself, which is when he actually asks the question?’

The captain scratched the top of her forehead, considering it.

‘Days, weeks, months . . .?’ Hunter suggested. ‘In that time, both witnesses could’ve very well learned the answer to that easy question.’

Again, Hunter gave the captain a few seconds to think about it.

‘On the morning of the murder,’ he proceeded, ‘Tanya Kaitlin could’ve decided to memorize her best friend’s number for whatever reason. John Jenkinson could’ve decided that this year he would go back to being a romantic husband and surprise his wife by remembering their wedding anniversary, bring her flowers, take her on a holiday . . . whatever. The killer had no real guarantees that they would actually get it wrong, Captain. The best he could do is go for a question that they should get wrong.’

Captain Blake stayed silent.

‘So he strengthens his chances with yet another clever trick,’ Garcia said, taking over. ‘Both of his second questions carried either a number sequence, or a date. It’s a proven fact that number sequences, formulas and dates are the hardest things for the average human brain to memorize.’

The captain couldn’t argue with that. She always had trouble remembering dates and phone numbers. Formulas? That was a definitely no-no.

‘So,’ Garcia continued, ‘going back to where we were: The killer hits them with his second question immediately after he gave them a false sense of security. Both witnesses have told us that with that second question, the first thing they did wasn’t to search their memory for the answer.’ Garcia shook his head. ‘No. They question the question: “What? What do you mean? Wait a second . . .” and so on.’

‘Big mistake.’ Hunter again. ‘By the time they actually start searching their memory for an answer, three maybe even four out of the five seconds the killer gives them are gone. And they know this, because he counts them down, which adds to the pressure. Now we have one more element. One that even if the numbers and dates are there . . .’ Hunter pointed to his own head, ‘. . . it could cause them to mix them up.’

‘Panic,’ Captain Blake said.

‘Almost, but not yet,’ Hunter disagreed. ‘What we’ve got is anxiety, nerves kicking in, maybe even a little fear. So just before the killer counts them down to zero, they blurt out the wrong answer, either because they don’t really know it – Tanya Kaitlin’s case – or their time is up and anxiety causes them to mix up the dates – John Jenkinson’s case.’ Hunter stepped away from the picture board. ‘With that, the killer finally shows them his trump card – the punishment for their wrong answer.’ He nodded at the captain. ‘Now we’ve got panic. And that’s why he used a pointy chisel instead of the hammer on its own.’

‘Too soft an impact,’ Captain Blake said, the puzzle finally solved in her head. ‘And all he would’ve had would’ve been a victim with a bump on the head. No pyramid splinter fracture. Too hard an impact and the victim would’ve either been dead too soon or have been knocked out with a concussion.’

‘Correct,’ Hunter agreed. ‘Neither case would’ve worked for our killer because with the first strike he needed two things to happen. One: He needed Cassandra Jenkinson to be in pain but stay conscious. Two: He needed to drive panic deep into her husband’s heart and consequently his brain. And what better way to do that than to make him watch his wife bleed?’

Captain Blake closed her eyes for an instant while shaking her head.

‘A light hit with a blunt instrument wouldn’t have caused her scalp to rupture,’ Hunter added. ‘For that, he would’ve needed a much more powerful strike, and controlling that would’ve been a problem.’

‘As soon as he’s got blood pouring down his victim’s face,’ Garcia took over again, ‘it’s game over, Captain. Even if the answer was right at the tip of his tongue, he wouldn’t be able to get it out because the final psychological element is the most destructive of all.’