Chris Mooney - The Secret Friend

'We may have another potential victim,' Bryson said. He told Chadzynski about Hannah Givens.

'Have either of you spoken to Dr Karim?' Chadzynski asked.

'I've left a message at his office over the weekend,' Darby said. 'I'm hoping he'll cooperate.'

'I'll take care of it,' Chadzynski said. 'Karim likes to push, and I like to push back. Keep me informed at every step.'

The commissioner stood. 'Good work on the necklace, Darby. Let's see what else we can find.'

When Darby arrived at the lab, she immediately went to Serology. Coop had set up in the back, near the grouping of windows with the strong light. Keith Woodbury was taking pictures.

The pink sweatshirt, nylon running pants, socks and sneakers were laid out on sheets of butcher paper. Like Emma Hale, Judith Chen's dirty clothing was ripped and snagged in several places from rocks, branches and other rough, sharp things she had bumped up against during her journey across the cold, dark bed of Boston Harbor. The clothes were dry but still carried the water's polluted, metallic odour.

Coop handed her a mask. 'Paperwork's all done, and Keith is almost finished the Polaroids,' he said.

'What about digital?' Darby always used digital pictures to augment her files.

'How long have we been working together?'

They each took an item of clothing and began the painstaking process of examining the fabric under the illuminated light magnifier.

Inside the running pants Coop found a long black hair. He examined it under a comparison microscope. The hair didn't contain a root bulb, which ruled out DNA analysis. Given the length, texture and colour, chances were the hair belonged to Judith Chen. He placed the hair inside a glassine envelope and went back to work.

The sweatshirt was stained with blood. The splatter pattern suggested that Judith Chen, like Emma Hale, was shot first and then transported to the destination where her body was dumped into the water. Darby wondered if their killer had used the same vehicle both times. She also wondered if Chen and Hale had known they were going to die. Given the advanced decomposition of the bodies, it was impossible to know if either woman had struggled or put up a fight.

'This is interesting,' Darby said. Using a pair of tweezers, she pointed to a tiny pale smudge on the right shoulder of the sweatshirt.

'What is it?' Coop asked.

'It looks like makeup.'

'What's that stuff you chicks put on your face and cheeks?'

'It's called foundation. Chicks use it to even out their skin tone.'

'Okay, so Chen smudged some of her makeup on her shoulder.'

'Look at the placement. It's too high on her shoulder. She couldn't have done that.'

'Maybe she wiped her hands on her sweatshirt.'

'Women don't wipe their hands on their clothes, Coop.'

'I think it's safe to assume she was being held under less than favourable circumstances.'

'If she wanted to wipe off her hands, she'd wipe them on her pants or the front of her sweatshirt. Why reach up and wipe it on her shoulder?'

'Good question.'

'This is probably oil based.'

'You've lost me.'

'The makeup is oil based as opposed to water based. If it was water based, we probably wouldn't be able to see it. All the time in the Harbor would have washed it away.'

Darby swung the illuminated magnifier over the stain. 'The colour is too pale,' she said. 'Chen's skin was darker. She wouldn't have used this shade. It's made for pale Irish chicks.'

'Emma Hale had pale skin. Maybe it belonged to her.'

'Then how did it get on Judith Chen's shoulder?'

'Maybe the guy who abducted Chen made them wear makeup.'

'Or maybe he wears makeup to cover a scar or a defect,' Darby said. 'Don't give me that look, Coop. I know plenty of men who use concealer to hide a pimple or a scar.'

'You mean guys like Tim Bryson?'

'I don't think Tim wears makeup.'

'He gets his hair cut at some fancy place on Newbury Street and he does yoga.'

'For the record, yoga is an amazing workout. You should try it sometime.'

'I'm strictly free weights, sister.'

'Which way would you go?'

'Sorry, but I don't swing that way.'

'Good for you. I was referring to the sample. Mass spectrometer or FTIR?'

Woodbury answered the question. 'FTIR has the better library.'

Darby nodded. While the mass spectrometer could isolate a sample's components, Fourier Transform Infrared Spectroscopy was a more sophisticated test. It would identify the organic and inorganic compounds found in a sample and compare them against its library in search of a 'molecular fingerprint'.

Darby took several close-up photographs of the smudge and then prepared the sample.

'I'll keep working on the clothes, see if I can find the print in the pant pocket,' Coop said. 'You two kids have fun.' FTIR had failed to find a unique match in its makeup library, but that didn't mean one didn't exist. The lab's FTIR system was only as good as its library.

On the FTIR computer screen was a bar graph listing the sample's various chemical properties.

'There's a large concentration of titanium dioxide,' Woodbury said. 'We also have paraffinum liquidum, cera alba, talc, isopropyl palmitate, magnesium carbonate, allantoin, propylparaben and copernicia cerifera. We also have one listed as unknown. Let's make sure we have the latest version of the makeup library.'

Woodbury checked the system. The makeup library had been updated early last month. He checked to see if there were any additional updates to download. There were none.

'Maybe it's not makeup,' Darby said.

'These are chemicals found in makeup, but which brand?' Staring at the monitor, Woodbury leaned back in his chair, rubbing a hand across the stubble on the back of his head. 'The problem is the sample listed as unknown. It's throwing the system off. We'll need to isolate it first.'

'Could FTIR give us a possible list of brands?'

'It could, but you could be talking hundreds of samples. The level of titanium dioxide is interesting.'

'Meaning?'

'It's rather high,' Woodbury said. 'Makeup – and that covers everything from foundation to products used to camouflage scars or pimples – contains traces of titanium dioxide, mica and iron oxides. Here, we have a higher than normal level of titanium dioxide. Did Chen have any scars on her face?'

'I don't think so. I'll have to check the photographs.'

'Did she use makeup?'

'She had some things in her medicine cabinet.'

'If I had the makeup she used, I could take samples and run tests against what we have here.'

'I'll make sure you get them.'

'Are you going to get them yourself or are you going to send someone there to retrieve them?'

'Why are you asking?'

'I don't know how to say this without sounding sexist, so I'll just say it. You're a woman.'

'Thank you for noticing,' Darby said.

'What I mean is you're more familiar with makeup than, say, a male patrolman who might rifle through her medicine cabinet or makeup kit and overlook something. For all I know, this sample is a zit cream with a camouflage tint.'

'Understood. I'll collect the samples myself.'

'The other thing is we may be talking one or more different samples of makeup – meaning you could have two different brands here. You may also want to get Emma Hale's makeup. If both of these women were held in the same place, maybe Chen used one of Hale's products.'

'How are you going to identify the unknown sample?'

'Let me see what I can do.'

That was Woodbury's way of saying he wanted some time alone to think. Darby knew he didn't like to work with someone hovering over his shoulder asking questions.

'I'll get you the makeup,' Darby said.

She was standing in her office, putting on her coat when she received a call from the station's front desk.