Two men named in Friday's announcement were suspected of being involved in Denise Marie Pierson's death. She was reported missing in April 1981, after failing to return home from Marcus Hook visiting a friend. Her body was discovered in Marcus Hook, about 300 yards from one of the suspects' homes in July 1984.
Wayne Anthony Walker (58) was arrested Thursday on multiple charges of murder, kidnapping, and conspiracy. Court records did not indicate if Walker had an attorney while he was in county jail for unrelated assault charges.
State Police investigators and Jack Stollsteimer, Delaware County District Attorney, announced that Peter Horne was a coconspirator in the young girl's death. Horne was also incarcerated on unrelated stalking allegations. Investigators stated that two additional individuals are being investigated for possible roles in the death and offered $5,000 for any information leading to further arrests.
"For over forty years, the family of Denise Pierson sought answers to the tragic death of their loved ones. "We hope today's announcement brings some closure and healing that they have been denied for too many years," Stollsteimer said in a statement.
Investigators interviewed Walker, Horne, and other suspects over the years. They also interviewed Walker after Walker allegedly gave details about the murder to a former cellmate while he was in prison. After a call to a trauma center, which claimed responsibility for Pierson's death, Horne was able to trace the call back to Horne. Although physical evidence, including "blackjack" batons, rope, clothing, and jewelry, was found over the years, investigators concluded that they didn't have sufficient evidence to indict the men responsible for Pierson's death.
In 2018, investigators reopened the case and discovered a 6-inch folding blade that was found with Pierson's remains. They interviewed former acquaintances of suspects again and started to piece together the details that many of the suspects had revealed over the years to potential witnesses.
Troopers contacted a forensic specialist at the Florida Institute of Forensic Anthropology and Applied Sciences University of South Florida to re-examine photos of the remains. He was able show Pierson sustained a puncture wound near her jawline from a sharp knife. Investigators claim that the knife and new autopsy information have helped to corroborate statements made by potential witnesses.
"As with any cold-case Homicide Investigation investigation, the passage of the time should not be viewed as a burden but an advantage. Many times, it is found that relationships change over the years. Witnesses, who might have been reluctant in the past to speak up, are now more open to helping. "People who were trusted by suspects in the past may not be as trustworthy 40 years later. This is what Trooper First Class Andrew Martin said.