A forensic scientist with the Pennsylvania State Police’s crime lab in Greensburg today described the discovery of semen, 30 years later, on items recovered from the bedroom of Catherine Janet Walsh.
It is the fourth day of testimony in the trial of Gregory Scott Hopkins, 67, a former Bridgewater councilman.
Walsh, a 23-year-old Monaca woman, was discovered by her parents on Sept. 1, 1979, in the bedroom of the apartment where she lived alone.
She wore a night shirt and was covered with a sheet, and her hands were bound with rope behind her back. Around her neck tightly was a handkerchief, which strangled her.
There was no evidence of recent sexual activity.
No one was charged in the death until January 2012, when Mr. Hopkins was charged with criminal homicide after DNA evidence, not known of in the 1970s, was recovered from the rope around Walsh’s wrists, the back of the nightgown and the sheet that covered her.
Mr. Hopkins has maintained his innocence.
James Ross, the Ambridge attorney representing him, has said that Mr. Hopkins’ DNA should be there, since he and Walsh had sex in her bed a few times, the last about four weeks before her death.
Today, he pressed again on that point during testimony given by Ashlee Mangan, a forensic scientist at the Greensburg crime lab, who studies bodily fluids.
Ms. Mangan, who began working on the case in late 2010, described how she used a tool called an alternate light source to identify stains not visible to the naked eye, which could indicate the presence of semen, saliva or other bodily fluids.
She described testing items that became visible under the light for seminal fluid, then looking further at a sample under a microscope.
On the nightgown, the top sheet and the rope, she said she found semen that rated a 4+, the top of the rating scale and signifying “an abundant amount of sperm.”
On the fitted sheet and the bathrobe, the semen stains did not exceed 1+, the lowest rating.
She sent the items on to be tested for DNA.
But Mr. Ross asked why Ms. Mangan only tested for semen, when the alternate light source found other stained areas on the items.
“What if other spots had saliva, for example, pointing to another suspect?” he asked.
He also had Ms. Mangan describe how the alternate light source and microscope examination does not show when or how the semen was left, and that semen discovered 30 years later could have been deposited weeks before Walsh’s death.
Responding later to questions posed by Brittany Smith, assistant district attorney for Beaver County, Ms. Mangan said that semen stains are not always visible to the human eye.
She said the amount she found on the rope, the nightgown and the top sheet was significant.
“Based on research and my experience, a 4+ rating is not consistent with being washed,” she said.
Judge Harry E. Knafelc is presiding over the trial, which is expected to continue into next week.
Kaitlynn Riely: firstname.lastname@example.org.
First Published November 15, 2013 4:59 PM