didn't mind demonstrating it. It was a measure of just how rattled she was that she was nervous now. She took a breath or two and turned round and nodded to the assembled policemen and women. 'As you already know we're putting her age at mid-twenties. Time of death between one o'clock and two o'clock last night.'
The young constable who had been guarding the body from the prurient gaze of the public earlier in the morning raised his hand.
'Can I ask a question?'
'Of course,' Kate said. 'What is it, Constable?'
'How can you be so sure about the time of death? What are the signs?' Danny Vine asked, his notebook open and his pen ready.
Amusement rippled round the room. Kate glared at them. 'All right. Some of you know as much about forensic pathology as I do – in your own opinion. But for the benefit of those who don't, there are a number of ways of determining time of death. It's a science but it's not an exact science. Rigor mortis usually sets in about three or four hours after death with full rigor about twelve hours later. Our victim hadn't reached that stage yet. So that's one thing. Ambient temperature plays a part though. Three to four hours is the norm with mild temperatures.'
'It was brass monkeys last night, ma'am.'
'Yes, thank you, Constable Wilkinson. You're right, it was bloody cold last night so that skews our calculations. But there are other factors we can use.' She looked across to see Danny Vine was taking copious notes. Keen to be a detective, she reckoned. She took a sip of water to allow him to catch up.
'Other conditions factor in. The age of the body, how active the person was prior to death. If they were very active then rigor mortis can set in quicker. We don't know what this woman was doing prior to her murder but at that time of night we can assume she hadn't been jogging on the heath. So we look at other indicators.' She pointed to the photos mounted on the display panels.
'The heart, as you all know, is a muscle that pumps blood around the body. Once that pump stops working, at the time of death, blood collects in the most dependent parts of the body. That is livor mortis. Then the body stiffens, which is rigor mortis, and then with no heat being generated post mortem, the body begins to cool and this is the algor mortis stage.'
She pointed at the blue staining on the body of the dead woman. 'Blood will collect in those parts of the body that are in contact with the ground. Most commonly the back and the buttocks when the person is lying face up. The skin is pale because all the blood that keeps it pink drains into the larger veins. It can take minutes or hours after death, but livor mortis will manifest itself on the skin.'
She pointed to a close-up photograph of the discoloration on the woman's face. 'These purplish blemishes are what embalmers call post-mortem stain. It takes a few hours but after that the blood becomes what we call fixed. That is, it won't move to other parts of the body if the corpse is moved. So we can use that to also determine where the murder took place. And, in this instance, together with the other factors such as the arterial spray in the immediate area, we can say pretty definitely that the woman was killed in the place where she was discovered.'
Kate walked back to the desk and took another sip of water. She was aware that Delaney was watching her but determined to keep professional.
'There is a condition, at the time of death, known as primary flaccidity.'
'Bob Wilkinson knows all about that,' a female officer called out from the back of the room, and laughter erupted. Kate smiled, the grim photos on the wall behind were testament to the seriousness of the situation but the laughter didn't mean anyone in the room wasn't focused on the dead woman, and finding justice for her. Black humour was just a coping mechanism, after all.
She held up a hand. 'All right, settle down. Constable Wilkinson is already no doubt well aware that there are medications available on prescription
