DNA analysis
NOTE: To assist you in understanding this document, the Crime Lab prepared a tutorial on Multiplex STR DNA analysis.
YOKNAPATAWPHA COUNTY FORENSIC LABORATORY |
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REPORT DATE: 7/15/2020 Madeline Holland, Ph.D. |
Analysis: Multiplex STR |
Case: 003419-11G-2020 |
Case Description: Philip Fontaine Homicide |
Investigative Agency: Yoknapatawpha County Sheriff's Department |
Investigating Officer(s): Det. S. Murphy. Det. T. Armstrong |
Evidence Item | Description |
003419-04-02A |
Chef's knife ‒ Sample location: 5cm from tip |
003419-04-02B |
Chef's knife ‒ Sample location: tip of blade |
003419-04-02C |
Chef's knife ‒ Sample location: handle |
003419-04-02D |
Chef's knife ‒ Sample location: blade/handle junction |
003419-S01 |
Blood sample from Philip Fontaine |
003419-S02 |
Presumed blood smear located on Philip Fontaine's left cheek |
003419-S03 |
Pooled blood near body on kitchen floor |
003419-S04 |
Presumed bloody fingerprint on kitchen cabinet door |
003419-S05 |
Shoeprint on kitchen floor |
003419-S06 |
Red substance on broken glass |
003419-S07 |
Red droplet on kitchen floor |
003419-S08 |
Red droplet on kitchen floor |
003419-S09 |
Red substance on kitchen sink |
Findings: Items 003419-04-02A and 003419-04-02D are positive mixtures as noted by 3 to 4 peaks at several loci. By comparing the electropherogram of the victim (003419-S01), items 003419-04-02A and 003419-04-02D contain the DNA of the victim. Items 003419-04-02B, 003419-S03, and 003419-S05 can be conclusively matched to the victim (1 in 625,000,000 probability the samples do not belong to the victim). Items 003419-04-02C, 003419-S02, 003419-S04, 003419-S06, 003419-S08 and 003419-S09 represent an unknown donor, who has contributed to items 003419-04-02A and 003419-04-02D. (1 in 750,000,000 probability that the unknown donor does not contribute to said items). Item 003419-S07 represents a third donor inconsistent with the victim or previous unknown donor. All unknown donors are male (Amelogenin locus containing 2 peaks). |