Salem Falls Part 32

200.

12, 12.

11,11.

Shirt 12, 12.

11,11.

Nails 12, 12.

11, (8).

Thigh N/A.

8, (11).

Item TH01.

VWA.

100.

6, 7.

17, 17.

200.

6, 7.

15, 15.

Shirt 6,7.

15, 15.

Nails 6,7.

17, (15).

Thigh 6, (7).

17, (15).

Item D16 S539.

D7 S820.

100.

12, 14.

9, 12.

200.

13, 13.

8, 8.

Shirt 13, 13.

8, 8.

Nails 12, 14. (13).

9, 12, (8).

Thigh N/A.

12, (8), (9).

Item D13 S317.

D5 S818.

100.

9, 13.

12, 12.

200.

11, 11.

10, 12.

Shirt 11, 11.

10, 12.

Nails 9, 13, (11).

12, (10).

Thigh 13, (9), (11).

12, (10).

"The one hundred line is the sample of blood that came from the victim. The two hundred line is the sample that came from the suspect. These are the standards ... the known samples that we use to compare everything else we get. The numbers in each of those boxes are alleles, found at different places on the DNA molecule. The DNA we extracted from the blood on the shirt, as you can see, is an identical match to the suspect's standard."

"So far," Matt said, "I'm a happy camper."

"Good. Because the fingernail residue is a slightly different story. The victim's own skin cells are naturally there, as well as some skin cells that are not hers."

"Like a mixture?" Matt asked.

"Exactly. You'll see numbers that correspond to the victim and the other party."

"Is that what the parentheses are for?"

"Yup. Different intensities, based on the combination of alleles from each person. Say, for example, that the suspect and the victim both have an eleven at the TPOX location ... but only the victim has an eight. In a combination of their DNA, I'd expect to find a thicker band at the eleven than I would at the 8. The parentheses suggest just that."

The waitress sailed over and slapped two chocolate milk shakes down on the table. "Thanks," Frankie and Matt said simultaneously.

They left the gla.s.ses sweating rings, their attention absorbed by Frankie's chart. "For the s.e.m.e.n, unfortunately, the results were inconclusive."

Matt's face fell. "Why?"

"There's no result in the CSF system and the D16 system. That's because sometimes, when there's not much DNA, we can't get readings at those loci."

Staring at the numbers, Matt frowned. "Can you tell me anything about it?"

"Yes. Since we're talking about s.e.m.e.n, I know it's going to be a mixture of the victim's inner thigh skin and some male's sperm."

"Like the fingernail residue?"

Frankie nodded. "Compare those two lines."

Matt studied the chart for a moment, then shrugged. "The numbers are all the same ... they're just mixed up in a few spots. That means you can't eliminate the suspect, doesn't it?"

"Technically, that's right," Frankie admitted. "But there's something there making me a little hesitant to finger him, too."

Matt tossed the papers down and leaned back in his chair. "Talk."

"Think of all the people in the world, and all the different alleles they've inherited. I've never seen a mixture of two unrelated individuals where I didn't have four distinct numbers at some some location. You'd think, just by probability statistics, that there'd be some place where the suspect would be-let's say-a twelve, thirteen and the victim would be an eleven, fourteen ... but not according to this." She pointed to the thigh a.n.a.lysis. "Look at the overlap. In fact, at only a handful of locations is there any number foreign to the victim's own DNA." location. You'd think, just by probability statistics, that there'd be some place where the suspect would be-let's say-a twelve, thirteen and the victim would be an eleven, fourteen ... but not according to this." She pointed to the thigh a.n.a.lysis. "Look at the overlap. In fact, at only a handful of locations is there any number foreign to the victim's own DNA."

"Are you telling me there's a lab error?"

"Thanks so so much for the vote of confidence." much for the vote of confidence."

"Maybe you didn't have enough DNA. Isn't it possible that if the sample was better, you might have gotten four alleles?"

"It's remotely possible," Frankie conceded. "But that's not all that's bugging me. Look at the TH01 system, for example. The victim and a suspect are both six, seven there, so a mixture of their DNA should always always be six, seven there." be six, seven there."

"It is."

"Not in the s.e.m.e.n sample. There's a lighter seven, along with the six. That doesn't make sense." She shook her head. "I'm not trying to ruin your case. But while I can't eliminate your suspect ... he's not the most perfect fit, either."

Matt was silent for a moment, tracing his finger through the wet stain the milk shake had left on the table. "C'mon, Frank. You could combine the DNA of every guy in Salem Falls with my victim's and still not come up with a precise textbook mixture."

Frankie considered this. "Maybe they're related."

"Suspect and victim? Not a chance."

"Well, then, the suspect you gave me to test ... and another guy who actually did contribute to the sperm sample. Relatives have DNA profiles that overlap ... which can sometimes account for bizarre results."

Matt exhaled slowly. "You're telling me my victim scratched the h.e.l.l out of the suspect, who bled all over her shirt ... and then brought his brother in to rape her?"

Frankie raised an eyebrow. "It's a possibility."

"It would be if the suspect had had a brother!" a brother!"