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Expert witnesses testify in Donachy murder case

October 13, 2011

RIDGWAY - Two expert witnesses from the Pennsylvania State Police crime labs testified on Wednesday during Lawrence Earl Donachy’s trial being held in the Elk County Courthouse. Donachy, 36, is charged in the April 6, 1999 rape and murder of Irene Challingsworth, a St. Marys beautician.
Forensic Lab Manager Bruce Tackett of the PSP Crime Lab in Erie, along with Forensic DNA Manager Beth Ann Marne of PSP Crime Lab in Greensburg, were both accepted as expert witnesses as part of the trial.
Tackett, who has worked in the forensic science field for over 27 years, specializes in serology, the study of blood and other bodily fluids.
In 1999, Tackett analyzed approximately 40 pieces of evidence in the Challingsworth case. He was requested to look for anything which might be foreign and could be linked to a suspect.
As part of the rape kit he analyzed, Tackett testified that no seminal material was found on swabs in 1999; however, the swabs were resubmitted by PSP-Ridgway for additional testing in 2002, which allowed him to utilize a new technique with more sensitive equipment which picks up lower levels of seminal fluid. As a result, he found semen present on the swabs.
He noted this technique was unavailable in 1999. The swabs were then sent away to PSP’s Greensburg lab for DNA analysis.
Tackett said he reviewed the rape kit in July 1999 and at the end of 2002, with a report of the results issued in March 2003.
Among the items he analyzed which contained Challingsworth’s blood were a piece of bloodstained carpet from the bedroom doorway; a pair of panties found near the foot of the bed; samples from walls surrounding her bed; three new pairs of panties with tags still attached containing small bloodstains found on them, which Tackett said were caused by impact splatter from her stab wounds; and a white pillowcase which contained heavy bloodstains on both sides.
Tackett said additional small bloodstains on the pillowcase were consistent with blood splatter. Also found on the case was a transfer pattern from a knife blade, which measured approximately one inch wide by six inches long. He also examined five additional pillowcases in which bloodstains were noted on all of them.
Challingsworth’s blue fleece nightshirt also had heavy bloodstains around the neck area, as well as the lower hem being charred and melted on the left rear side.
Tackett said her bra, used as a ligature around her neck, was covered in blood and contained a clump of her hair.
Additional pieces analyzed were panties, a sanitary napkin, a purple fiber, a pillow, a burned section of the bedspread, a charred piece of fabric from below the bedspread, a kitchen knife, sink drain stopper, vials of water collected from the bathtub, and a drainpipe from the bathroom sink.
Some of these items contained blood; however, there was an insufficient amount to use for analysis, according to Tackett.
Tackett testified that he identified a semen stain in the upper portion of the fitted bedsheet. He sent this on to the PSP Greensburg lab for DNA analysis. Also found on the sheet were blood and urine stains, along with a small area of soot from the burn mark.
Tackett explained that pantyhose used to restrain Challingsworth’s wrists, the pillowcase and her nightshirt were resubmitted for further analysis in 2008, as new technology had come about to test for DNA. Any results or conclusion from the resubmission for analysis and DNA testing was not revealed during Tackett’s testimony Wednesday.
Marne was the second expert witness to testify. Prior to overseeing the DNA program inside the PSP Greensburg lab, she worked as an analyst and supervisor at the facility. Marne explained DNA as a genetic blueprint each individual possesses with characteristics that make us unique from one another. DNA is unique from person to person, with the exception of identical twins.
She stated in 1999, the lab utilized first-generation technology testing in DNA, which was a very common type of testing in labs across the U.S. Since then, second-generation testing has evolved in which scientists can identify 16 areas instead of the previous six areas in 1999.
On June 3, 1999, the lab received Tackett’s samples, which Marne began processing on June 15.
Marne testified that she performed a DNA analysis by developing a profile with genetic characteristics from the semen stain on the bedsheet. Following standard procedures, a successful genetic profile was created.
In January 2001, the lab was requested to re-test the DNA, during which time which scientists took advantage of new technology that had been developed.
The trial resumes Thursday at 9 a.m.

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