Cold Case Reopened
Scientific progress over the years following Sandy's murder increased the chances that her killer might be identified and brought to justice. Armed with the ability to conduct DNA analysis on evidence items previously untested, in addition to those subjected to serological testing, investigators reopened the case.
New Methods for Old Evidence
The cold case squad reopened Sandy Doe's case. Upon locating the crime scene evidence, it was submitted to the laboratory for DNA analysis.
DNA - Unknown Samples (new page)
The laboratory obtained a 13-loci DNA profile, consistent with a single male donor, from a cigarette butt recovered outside the window at the crime scene. The laboratory labeled this profile as "unidentified source #1."
A New, Unknown Person of Interest
The screwdriver (both handle and end) was swabbed for DNA. The 13-loci DNA profile obtained from the end of the screwdriver was consistent with that of the victim.
DNA - Physical Evidence Report (PDF)
A mixed DNA profile from at least two sources was obtained from the handle of the screwdriver. The victim was excluded as being a contributor. However, "unidentified source #1" (single male donor) could not be excluded as a possible contributor.
Narrowing the Possibilities
The laboratory recommended that reference samples be obtained from Lucy Johnson and her mother Carol Johnson. Once investigators obtained the reference samples and the laboratory developed the profiles, Lucy Johnson was excluded as a contributor to all physical evidence items submitted for DNA analysis.
DNA Lab Report - Reference Samples (PDF)
It was determined that Carol Johnson could not be excluded as a contributor to the mixed DNA profile obtained from the screwdriver handle.
Additionally, an 11-loci DNA profile was obtained from the sperm fraction of the vaginal swab. The remaining two loci were inconclusive. The 11-loci profile was consistent with unidentified source #1 (single male donor).
Using a Specialized Lab
There was not sufficient root material to conduct short tandem repeat (STR) DNA testing on the hair recovered from Sandy Doe's bedding. Therefore, the pubic hair was submitted to a specialized laboratory for mitochondrial DNA (mtDNA) testing.
mtDNA Lab Report - Pubic Hair (PDF)
The mtDNA profile obtained from the hair was consistent with Sandy's mtDNA profile.
An NDIS Hit
Joe Smith had recently been released from prison, where he served time for burglary. When he was convicted of the burglary, state law required Joe Smith to submit a DNA sample for upload into the Combined DNA Index System (CODIS).
The 13-loci DNA profile from the cigarette butt was uploaded to the National DNA Index System (NDIS) and searched. A hit was reported with a known offender profile named Joe Smith. The NDIS hit was sufficient evidence to secure a warrant to obtain a DNA sample from Joe Smith.
A Warrant Obtained
The laboratory compared the newly obtained reference sample from Joe Smith to that from the crime scene evidence. The laboratory reported that Joe Smith's DNA profile matched the profile developed from the cigarette butt at all 13 loci. Additionally, the laboratory reported that Joe Smith was consistent at all 11 loci developed from the sperm fraction of the vaginal swab and he could not be excluded as contributing to the mixture contained on the screwdriver handle. This information was reported to the investigators who subsequently obtained a warrant to arrest Joe Smith for the rape and murder of Sandy Doe.
Evidence
- Crime Scene Sketch (JPG)
- DNA Lab Report – Physical Evidence (PDF)
- DNA Lab Report – Reference Samples (PDF)
- Autopsy Report (PDF)
- mtDNA Lab Report - Pubic Hair (PDF)
- Serology Report (PDF)
Original Evidence Collected
From the crime scene:
- Cigarette butts (all from the same brand)
- Bedding
- Pubic hairs
- Screwdriver
ABO blood typing confirmed that the blood on the end of the screwdriver was consistent with Sandy Doe.
From the victim:
- Blood
- Fingernail clippings
- Oral and vaginal swabs
- Head and pubic hair
Evidence Submitted for Forensic DNA Testing
From the crime scene
- Cigarette butts
- Pubic hairs
- Screwdriver
From the victim:
- Blood (reference sample)
- Vaginal swab
- Pubic hair
- Fingernail clippings
Other (reference samples):
- Blood from Lucy Johnson
- Blood from Carol Johnson
- Blood from Joe Smith
Nuclear STR DNA Analysis
Nuclear STR DNA analysis was performed on swabs taken from the screwdriver (both the handle and the end).
The STR DNA profile obtained from the end of the screwdriver was consistent with that of the victim. A mixed STR DNA profile from at least two sources was obtained from the handle of the screwdriver. The victim was excluded as being a contributor to this mixture.
Nuclear STR DNA analysis was performed on a cigarette butt recovered from the crime scene.
The STR DNA profile obtained from the cigarette butt was consistent with a single male donor (unidentified source #1). This result was compared with the results of the mixture obtained from the screwdriver. The male donor (unidentified source #1) could not be excluded as a contributor to the mixed STR DNA profile obtained from the handle of the screwdriver.
Nuclear STR DNA profiles were developed from the blood samples of Lucy and Carol Johnson.
Upon comparing their profiles with the mixture results obtained from the handle of the screwdriver, Lucy Johnson was excluded. However, Carol Johnson could not be excluded as a contributor. Assuming only two sources, the mixed profile found on the screwdriver handle was consistent with the combined STR DNA profiles from Carol Johnson and unidentified source #1 (single male donor).
Nuclear STR DNA analysis was performed on the vaginal swab obtained from the victim during the original autopsy. The STR DNA profile obtained from the sperm fraction of the vaginal swab was consistent with unidentified source #1 (single male donor) at 11 of the 13 loci. The two remaining loci were inconclusive.
Note that the laboratory reported that the DNA profiles obtained from the cigarette butt, the mixture obtained from the screwdriver handle and the sperm fraction of the vaginal swab were all consistent with one another.
mtDNA Testing
Because the pubic hair recovered from the crime scene had insufficient root material to conduct STR DNA testing, the sample was submitted to a private laboratory that specializes in mitochondrial DNA (mtDNA) testing. The mtDNA profile obtained from the crime scene hair evidence was consistent with Sandy Doe’s mtDNA profile.
