Evidence: Analysis of blood evidence

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Evidence: Analysis of blood evidence

To asssit you in understanding this document we have prepared a tutorial on Multiplex DNA Analysis available here.

YOKNAPATAWPHA COUNTY FORENSIC LABORATORY

DATE Analysis Performed: 12/10/03

Madeline Holland, Ph.D.
555 Jackson Avenue
Oxford, MS 38655
662-234-XXXX(FAX 662-234-XXXX)

Analysis: Multiplex STR

REPORT OF FORENSIC SEROLOGICAL ANALYSIS

Case Descripton: James Swarthmore Homicide

Case # 002202-18-2003

Investigative Agency: Yoknapatawpha County Sheriff's Department

Investigating Officer(s): Det. S. Murphy. Det. T. Armstrong

The following evidence items were tested presumptively for blood. Items showing a positive reaction were subjected to Multiplex STR analysis.

Evidence Item	Presumptive Test
000183-06-1: Knife of set of kitchen knives of the butcher’s block holding stand, blade length of 7.5cm, maximum width of 1.8cm.	Negative
000183-06-2A: Butcher knife of set of kitchen knives of the butcher’s block holding stand, blade length of 11.3cm, maximum width of 3.3cm. 5cm from tip.	Positive
000183-06-2B: Butcher knife of set of kitchen knives of the butcher’s block holding stand, blade length of 11.3cm, maximum width of 3.3cm. Tip of blade.	Positive
000183-06-2C: Butcher knife of set of kitchen knives of the butcher’s block holding stand, blade length of 11.3cm, maximum width of 3.3cm. Handle.	Positive
000183-06-2D: Butcher knife of set of kitchen knives of the butcher’s block holding stand, blade length of 11.3cm, maximum width of 3.3cm. Blade/handle junction.	Positive
000183-06-3: Filet knife of set of kitchen knives of the butcher’s block holding stand, blade length of 8.2cm, maximum width of 1.3cm.	Negative
000183-06-4: Paring knife of set of kitchen knives of the butcher’s block holding stand, blade length of 5.3cm, maximum width of 1.3cm.	Negative
000183-09: One (1) walking cane, sword tip inside the cane	Negative
000183-12: One (1) folding knife, mother of pearl handle	Negative
002202-01: Blood sample from James Swarthmore	Not Done
002202-02: Presumed blood smear located on James Swarthmore’s left cheek	Positive
002202-03: Sample from assumed pooled blood of victim	Positive
002202-04: Presumed bloody fingerprint on kitchen cabinet door	Positive
002202-05: Footprint on kitchen floor	Positive
002202-16: Red substance on broken glass	Positive
002202-17: Red droplet on kitchen floor	Positive
002202-18: Red droplet on kitchen floor	Positive
002202-19: Red substance in kitchen sink	Positive

Positive samples were analyzed using the AmpFlSTR® SGM Plus™ kit.

Electropherograms of evidence items:

Item #	Electropherogram
000183-06-2A
000183-06-2B
000183-06-2C
000183-06-2D
002202-01
002202-02
002202-03
002202-04
002202-05
002202-16
002202-17
002202-18
002202-19

Results: Items 000183-06-2A and 000183-06-2D are positive mixtures as noted by 3 to 4 peaks at several loci. By comparing the electropherogram of the victim (002202-01), 000183-06-2A and 000183-06-2D contain the DNA of the victim. Item 000183-06-2B, 002202-03, and 002202-05 can be conclusively matched to the victim (1 in 625,000,000 probability the samples do not belong to the victim). Items 000183-06-2C, 002202-02, 002202-04, 002202-16, 002202-18 and 002202-19 represent an unknown donor, which has contributed to items 000183-06-2A and 000183-06-2D (1 in 750,000,000 probability that the unknown donor does not contribute to said items). Item 002202-17 represents a third donor inconsistent with the victim or previous unknown donor. All unknown donors are male (Amelogenin locus containing 2 peaks).

Evidence Item