|Prosecution Witness: Annette Davis|
|Written by Mike Mayleben|
|Friday, 06 May 2011 18:38|
Direct Exam: Travis Vieux
She has been a forensic scientist for 21 years. She attended Ohio University and did an internship at the Miami Valley Crime Lab where she now works doing DNA analysis and she's also worked in fingerprinting. Previously she worked for Hamilton County. She attends meetings and conferences on an annual basis to stay current on new technology and also trains evidence technicians. She has testified as an expert over 100 times in several Ohio counties.
She began by explaining how she logged in evidence from the police to the lab. It comes in with a submission sheet, telling the lab what they expect them to find from the item and the item is then given a unique bar code.
The lab received the Lysol wipe that was found on the edge of the tub and it was tested for blood and semen but neither was found. She also received evidence from the tub drain which included water from the drain, the actual metal drain and the drain stopper. The water was packaged in a metal can, like a paint can, which caused it to rust, but Davis said it was still properly packed and she was still able to perform a test. All those items tested negative for blood but, she explained, it would determine how much water and blood were mixed to find the blood. She might not find blood if there was a large amount of water. She also tested the items of clothing, the bath mat and the towels from the bathroom for blood and semen but didn't find any on those items.
A photo is put on the screen showing the bedroom with different areas of the carpet removed. There are post-it notes on the photo in certain areas. The information she was provided was that the carpet was from near the bathroom door. She took photos prior to testing.
Wearing latex gloves on her hands, she then opened a Kroger brown paper bag and pulled out a sample of carpet and foam backing. She said she sees quite a bit of that kind of evidence packaging because paper bags breathe and the contents don't mold. The post-its on the photo showed which carpet sample was from which spot on the floor. A large piece of carpet from under Sarah's head showed a blood stain and Vieux pointed out brown/yellow stains. She said it tested positive for blood and fecal matter. The sample that was under her hips also tested positive for blood and fecal matter. The fecal matter had human protein in it so it wasn't the dog's.
She showed photos of the carpet samples prior to testing and then, looking at the samples in court, the stains were larger. She said when the carpet samples were packaged they must have been wet which diluted the stain and made the bag wet because there was a dry stain the bottom of the package for one of the samples. The blood stains had also soaked through to the back of the carpet. She said in her
opinion, there was water mixed with blood and it was diluted. It was more concentrated on one end of the sample than the other so the stain ran down the fabric and "wicked" off the edge. When samples are retrieved only a piece of stain is collected, not the entire stain. However, in this case, she received the entire stain. She placed clear plastic tape on that stain so that no one would have a bio-hazard
exposure but there was no compromise to the sample itself. Davis said she is also trained to recognize stain patterns and one sample from the area near the bedroom door showed three very faint smear stains and she thought it might be a finger swipe across the surface. The stain didn't soak through to the back of the carpet.
She did a DNA analysis of the material found under Sarah's fingernails and the left hand had primarily Sarah's DNA with a small amount of a foreign DNA, but the right hand had Sarah's and another unknown female DNA. She collected DNA from 2 female nurses, Sgt. Elliott and Sarah's mother, but nothing matched. Nothing further.
Cross Exam: Lindsey Gutierrez
She said she received the evidence in August but did not test it until either October or November, 2008. She thought she did some testing in Oct. and some in Nov and except for the carpet, there was no blood found on anything else.
Gutierrez asked her to step down off the stand to show her the carpet samples. She said the samples that had soaked through the bag were dry when she saw them. They sat on a shelf for about 2 months.
She couldn't say how large the stain actually was because blood was mixed with water and the stain ran down the carpet, getting pulled through to the back. She said she is familiar with the nylon blend carpet because the lab gets many samples like that. Wet stains soak through to the back because of the material. She acknowledged that the carpet sample had to be wet when it was packaged because of the leak. The fecal sample was also wet when it was packaged, because it also ran. She didn't see any evidence showing that anyone stepped in the wet fecal matter. She performed a test on the fecal matter, looking for a human protein component.
Regarding the DNA scrapings from Sarah’s fingernails, she said there wasn't enough DNA on the left hand to determine if it was male or female, but the unknown DNA on the right hand was female, but after comparing it to four females, she didn’t find a match. DNA can't just be tested to find out who it belongs to, it must match with another sample. She said there was no reason to test for DNA in the blood from the carpet samples because there was no reason to think anyone else was bleeding.
Davis said she didn't test the water spout or faucet handle because no sample was given to her. She said she would have preferred the water sample to be in a glass container or something that would not have rusted. She didn't have any information on how full the bathtub was so it would be hard to detect how much blood was in the water if there was not a large amount of blood. Nothing further.
Re-direct: Travis Vieux
He asked one question about the fecal matter, confirming there was enough to run down
the carpet, then nothing further