Man Charged In 40-Year-Old Delco Cold Case Murder

MARCUS HOOK, PA — Delaware County and state authorities said a man has been charged in connection with the 1981 cold case murder of an 18-year-old Marcus Hook woman on what would have been her 59th birthday.

Wayne Anthony Walker, 58, is charged with criminal homicide, first, second, and third degree murder, kidnapping, and conspiracy.

Walker is accused of killing Denise Marie Pierson, an 18-year-old Marcus Hook resident who disappeared on the night of April 14, 1981.

Authorities said three others were involved in her death: Peter Horne, who is deceased, and two others who are only referred to as "Suspect 1" and "Suspect 2" in documents provided by authorities.

There is a $5,000 reward for information that leads to the arrest of the other suspects. Anyone with information should contact Trooper First Class Andrew J. Martin, Criminal Investigation Assessment Unit, Pennsylvania State Police, Troop K, Philadelphia, at 215-452-5216.

State police reopened the case in 2018 and began reviewing existing, as well as new, evidence.

In the course of their review, investigators learned of the existence of a 6-inch folding knife that had been recovered with Pierson's remains, and stored by the Delaware County Coroner’s Office. This discovery led to a further examination of the evidence gathered regarding Pierson's remains, which provided information leading to the charges filed Friday.

District Attorney Jack Stollsteimer and Captain James B. Kemm of the Pennsylvania State Police announced charges today against Wayne Anthony Walker, 58, in connection with the murder of Denise Marie Pierson, an 18-year-old Marcus Hook resident who disappeared on the night of April 14, 1981. Pierson's remains were discovered in July 1984. An autopsy conducted in 1984 determined that Pierson died as a result of blunt impact injuries to the head, and the manner of death was homicide.

On April 14, 1981, Pierson did not come home from a visit to a friend’s house in Marcus Hook.

In January 1984, the Crisis Intervention Center at Crozer-Chester Hospital got a call from an unidentified caller who said he killed Pierson.

The call was traced to Horne's home in Marcus Hook.

A search warrant was executed at the Horne residence, and two blackjacks (leather Billy clubs) were recovered.

Horne denied making the calls to the crisis center.

In February 1984, investigators interviewed the owner of a garage that employed Horne, who confirmed that Pierson's mother had her car serviced at the garage. Pierson's mother confirmed that Pierson was with her on several occasions at the garage. Investigators determined that Horne left his employment with the garage the day after Pierson's disappearance.

On July 18, 1984, Pierson's skeletal remains were found in the vicinity of the railroad tracks at 7th and Market streets in Marcus Hook, about 300 yards from the Horne residence.

A 1984 autopsy showed Pierson died as a result of blunt impact injuries to the head, and that her manner of death was homicide.

In March 1994, investigators conducted an interview of Suspect 1, who said Pierson came to his apartment on the day of her disappearance.

He said Pierson was “naïve” and “trusting," and that he believed that Walker and Suspect 2 were capable of the murder.

In June 1994 investigators conducted a search of the residence previously occupied by Horne.

Items seized from the crawl space included segments of rope and multiple pieces of cardboard boxes.

Then in August 1994, investigators got information from a former cellmate of Walker.

Walker admitted to his cellmate he had been at a party at Horne’s residence with Pierson and others, including Suspect 1, authorities said.

According to the cellmate, Walker stated that at one point Horne and Pierson left the party to go to Delaware. When they returned to the residence, the victim was upset and called her mother.

Suspect 1 grabbed the phone and Horne hit her in the head with a black stick, authorities said. Horne, Suspect 1, and Walker carried Pierson to the train tracks, according to authorities.

Walker admitted to helping Suspect 1 and Horne with burying Pierson, authorities said.

From 1994 and 1995, investigators interviewed Walker on numerous occasions, who said he was at Horne’s house when Horne, Suspect 1, and Suspect 2 killed Pierson, according to authorities.

Walker told investigators that on the day of the incident, they played a game called "spin the stick."

During the game, Pierson charged for the door in an attempt to flee the residence.

Walker said that Horne then hit Pierson with a stick and she started to bleed, according to authorities. Suspect 2 provided Horne with clothes line which he used to tie up Pierson, authorities said.

Horne put Pierson in green trash bags then he, Suspect 1, and Suspect 2 carried Pierson to a wheelbarrow on the patio, according to authorities

Walker said they all took Pierson to the "tracks" behind the Marcus Hook school parking lot, where they removed the trash bags and Suspect 2 hit Pierson with a railroad spike, authorities said.

Walker said Pierson was not buried and that they just covered the body with bushes, according to authorities.

Walker said he was threatened by Horne and Suspect 1 to keep quiet about the murder. Walker told investigators he returned to the site where Pierson was dumped to have sex with her corpse, according to authorities.

In December 1994, based on information provided by defendant Walker, investigators conducted a search around the concrete storm sewer junction box in Marcus Hook. Investigators recovered rope, clothing, debris and a piece of jewelry. Investigators conducted a forensic analysis of the rope recovered from the storm sewer junction box and the rope recovered from the Horne residence. It was determined that the twine within the rope was similar.

In June 1995, investigators spoke with Horne's.

She confirmed that he kept a wheelbarrow at the house, as well poles with several clotheslines.

She also stated that Horne kept a weapon hidden in the basement of the residence.

A search warrant was executed and a .32 caliber derringer style handgun was recovered, as well as a Billy club.

Horne was subsequently arrested for firearms violations.

Horne was again arrested in 1997 on charges of stalking and was subsequently sentenced to a minimum of 6 years and 6 months to 19 years incarceration at State Correctional Institution – Mercer. Horne died while incarcerated in 2013.

Investigators re-interviewed Horne’s wife in March 2013.

During the interview, she admitted that she had been told to lie by Horne when investigators asked about the blackjacks that had been found at the residence, authorities said.

She said she believed that Horne had killed Pierson.

In 2018, investigators began to conduct numerous interviews of current and past acquaintances and family members of all involved suspects.

They learned that as time had passed, the suspects had begun to discuss details of the murder of Pierson with numerous acquaintances.

Investigators began to compile and corroborate these details with case facts and evidence.

In July 2021 Trooper First Class Andrew Martin engaged the services of Forensic Anthropologist Erin Kimmerle, Ph.D., Florida Institute of Forensic Anthropology and Applied Sciences at the University of South Florida.

Kimmerle conducted an overall review of the Medical Examiner’s report, notes, and photographs regarding Pierson's remains.

She also reviewed the case evidence amassed by the Pennsylvania State Police. In October 2021, Kimmerle issued a report based on her re-examination of the evidence and found that Pierson sustained a sharp incised cut along the right mandibular notch, which is the area in the skull above the jaw and adjacent to the ear.

She further stated that the puncture wound was an injury resulting from a sharp-edged object, and that the cut occurred at the same time as other injuries.

Kimmerle opined that the blunt and sharp injuries observed and described were consistent with having been inflicted by the recovered 6-inch folding knife, as well as the recovered blackjacks from Horne’s residence.

Kimmerle’s discovery of the knife wound aided investigators in corroborating witness and suspect statements.