Fairmount Park rape suspect arraigned on charges including murder and rape

The man who police now believe was the so-called Fairmount Park rapist — a previously unknown assailant who attacked four women in parks nearly two decades ago, killing one of them — was arraigned Wednesday morning on charges including murder, rape, and related offenses.

Elias Diaz, 46, remained in jail without bail. He had been taken into custody earlier this week on a separate set of crimes after allegedly slashing several people in Pennypark Park last month with a machete.

Following that arrest, investigators made the discovery that Diaz was also the same person they’d recently identified as a suspect in the decades-old rape cases. Those past attacks, which occurred between 2003 and 2007, had been unsolved for years, but police said Tuesday that forensic genealogy helped them finally identify Diaz in the spring as the alleged perpetrator.

Still, at that time, officials weren’t sure where Diaz was — or if he was even alive. Family members across the mainland U.S. and Puerto Rico had long been estranged from him, officials said. Some believed he could have been dead.

Then, over the weekend, police arrested Diaz for the November assaults in Pennypack Park, crimes in which they said he slashed people with a large knife while riding past them on his bike. He was arraigned and jailed Monday on charges including aggravated assault.

Investigators quickly came to realize Diaz was also the suspect in the older attacks as well. Police submitted further DNA samples for testing to confirm a match, and prosecutors approved the additional charges late Tuesday.

Diaz is now formally accused of raping and fatally strangling Rebecca Park, a 30-year-old medical student who had gone out for a jog in Pennypack Park in July 2003. Her body was discovered four days later in a shallow grave, a few yards off the trail where she’d gone for a run.

Authorities also believe Diaz attacked three other women around the same time: a 21-year-old he allegedly raped at knifepoint in April 2003 near Kelly Drive and Fountain Green Road; a 37-year-old who managed to fight him off on Martin Luther King Drive near Falls Bridge in October 2003; and a 29-year-old whom he raped and robbed in Pennypack Park in 2007.

Diaz has not yet been charged in those assaults, but will remain behind bars without bail for his murder case. Officials said their investigation is ongoing.

For nearly 20 years, police only had a general description of what the assailant in the sexual assaults looked like. And although Diaz had been arrested twice in the years since, both were for comparatively minor offenses — once for a drug case, the other time for failing to appear in court on the drug case, police said.

Police said Tuesday that they weren’t sure where Diaz had been living in the years between his alleged rape spree and the more recent string of knife attacks. They said they think he’d largely been homeless, most recently living in a shelter he built in the Pennypack Park woods.

Diaz did not have an attorney listed in court documents in his new murder case.

This is a developing story that will be updated.