Denise Pierson cold case: Officials announce charges relating to 1981 murder in Delaware County

Wayne Anthony Walker (R) has been charged in connection with the murder of, Denise Marie Pierson (L), an 18 year-old who disappeared in 1981 and was found dead in 1984. (Delaware County District Attorney's Office/Pennsylvania State Police)

MEDIA, Pa - Pennsylvania State Police and the Delaware County District Attorney’s Office announced charges in connection to the 1981 murder of Denise Pierson, on Friday afternoon.

Pierson was an 18-year-old Marcus Hook resident who disappeared on April 14, 1981. Her remains were found in July 1981 and an autopsy determined the manner of death as homicide by blunt impact to the head.

According to authorities, 58-year-old Wayne Anthony Walker has been charged with criminal homicide, kidnapping, conspiracy, first-degree murder, second-degree murder and third-degree murder. Walker is currently serving a sentence at the George W. Hill Correctional Facility on unrelated charges, according to the DA’s office.

Another man, Peter Horne, was identified as a co-conspirator in Pierson’s murder. Horne died before he could officially be charged.

Pennsylvania State Police reopened the cold case in 2018 and began working closely with the Delaware County District Attorney’s Office. While reviewing evidence, new investigative tools led authorities to a six-inch knife recovered with Pierson’s remains.

At the time of Pierson’s disappearance, an anonymous man called Crozer-Chester Hospital and said he killed Pierson. The call was traced to Horne’s home in Marcus Hook, but Horne denied making the calls.

In 1984, investigators began looking at the garage that employed Horne and learned Pierson had been there with her mother who had her car serviced at the location.

Two additional suspects are under investigation as detectives learned new information about the 40-year-old case.

One of the unnamed suspects told investigators in March 1994 that Pierson came to his apartment on the day of her disappearance. Months later in June 1994, Walker admitted to a cellmate that he attended a party at Horne’s home with Pierson and others, including one of the suspects.

According to the DA’s office, Walker told police Horne and Pierson left the party to go to Delaware and when they returned, Pierson was upset and called her mother. Police learned one of the unnamed suspects grabbed Pierson’s phone and Horne hit her in the back of the head with a black stick.

Peter Horne, who is deceased, was identified by authorities as a co-conspirator in Pierson’s murder. (Delaware County District Attorney's Office/Pennsylvania State Police)

Horne, the suspects and Walker then carried Pierson to the train tracks behind the Marcus Hook school parking lot after allegedly tying her in clothesline and placing her in trash bags.

In the following years, investigators re-interviewed people who knew Walker, Horne and the two additional suspects. The knife found at the scene body became a relevant piece of evidence in July 2021 when a forensic anthropologist found that Pierson also had a cut on the right side of her head.

"Sadly, this case has an extremely long and complicated history. As the chronology demonstrates, over the decades, investigators continued to work the case, but were unable to reach the threshold that would permit them to bring charges. Today, with the assistance of an expert in forensic anthropology, we are finally able to provide the victim’s family with answers about what happened to their loved one," said Delaware County District Attorney Jack Stollsteimer.

A $5,000 reward is being offered for information that leads to the arrest of additional suspects involved in the murder. Anyone with information can contact Pennsylvania State Police at 215-452-5216.