Nocturnal

Hair of the Dog

Robin lifted her head from the microscope.

That couldn’t be right. She must have mistakenly used a human hair.

She reached for the tray that contained the inch-long brown hairs she’d collected from the body and the blanket. With a tweezers, she carefully selected one that had been embedded in Oscar’s wound. She picked it up, held it close — yes, that was one of the animal hairs.

But it looked the same as her current sample.

She held them side by side: exactly the same.

She put the new one under the microscope. Just as she had done with the first sample, she started at low magnification to see the entire shape. The hair had a tapered end, as would be expected from animal fur. Ends of human hair were almost always cut, something that could easily be seen under a microscope, while most animal fur tapered to a point because the strands of fur wore down on their own.

At higher magnification, things got weird.

Hair or fur has three parts: the cortex, the cuticle and the medulla. Comparing it to a pencil, the cortex is the wood, the medulla is the lead and the thin coat of yellow paint is the cuticle.

The cuticle is a layer of cells that covers the shaft, like scales on a snake. The pattern of scales differs from species to species. Crownlike scales, called coronal, are common among rodents. Triangular spinous scales indicate cat hairs.

The sample Robin examined had imbricate, or flattened, scales.

Dog fur had imbricate scales, but those scales were thick sheets that wrapped all the way around. The scales on the sample from the blanket, however, were thinner, finer and tighter than would be found in dog fur.

This type of imbricate scales were found on human hair.

She checked a third strand, a fourth, then a fifth. All had fine scales, all had tapered ends.

Maybe the attacker had hair that grew very slowly. Maybe he rarely, if ever, had to get it cut. Maybe the strands were from a man with a receding hairline, his follicular growth slowed to a near standstill. Guys who were balding didn’t like trimming what little hair they had left.

Possible, but then there were the bite marks, the parallel gouges on Oscar Woody’s bones. Those had to be from an animal. A big animal. Sure, a handler and a big animal working together could account for the damage, and the handler’s hair could have been in the wound, but with that level of contact so would some fur from the animal.

The STR results from the saliva would soon be finished. If that came back as human, it would correlate with what she saw in these hairs. She could confirm the hair as human, however, by finding samples that still had follicles attached to the root end, then running the tests on those follicular cells.

Human or animal, soon she would know for certain.