(NewsNation) — An alleged serial killer in Washington State has been accused of luring four victims to the woods to help him dig up buried gold over the last few years.

Richard Bradley Jr., 40, was charged in May 2021 with the killing of 44-year-old Brandi Blake and has been sitting in jail since, awaiting trial on murder, arson and gun charges.

However, his case has ramped up over the weekend after he was hit with three additional counts of murder, according to The Seattle Times.

Authorities were able to connect the cases on one detail: The alleged killer lured the victims into the woods with the promise of buried treasure.

Blake went missing in 2021, and shortly after, was found dead of blunt force injuries in a Seattle-area park. She had won $20,000 at a casino and, like Maturin, was known to carry large amounts of cash, according to court documents.

Just 30 feet away from her shallow grave, investigators discovered human ribs.

Through DNA analysis, investigators learned the ribs belonged to 36-year-old Emilio Maturin, who was last seen alive back in 2019. His girlfriend reported him missing two weeks later.

According to court documents, she told detectives that she overheard Bradley telling Maturin that “he needed help digging up some buried gold in Auburn.” Maturin initially was skeptical, she told detectives but allegedly went along anyway. Maturin was in the habit of taking large amounts of money with him whenever he left the house, according to the court documents, and he had roughly $15,000 in cash when he left that day in his recently purchased BMW.

The girlfriend tracked Maturin’s cellphone to Game Farm Park in Auburn and went to look for him but got scared and left, according to charging documents.

Several hours later, Auburn police found an unregistered BMW parked near a large field at the park and waited for the driver to return. When they attempted to stop the driver, the car took off. Bradley was arrested after a car and foot chase and charged with eluding police, according to charging documents.

Bradley was charged with murder in Maturin’s death on Dec. 5 of this year.

In 2021, Michael Goeman, 59, and his son, Vance Lakey, 31, were found shot to death on a road not far from the same park where the others were discovered. Goeman received a large inheritance just before he and his son were killed, according to court documents.

Bradley was considered a person of interest in the deaths at the time. He was charged that May with second-degree arson after prosecutors said he offered a man $1,000 to set fire to the father and son’s impounded SUV.

On Thursday, prosecutors added two counts of second-degree murder.

All four victims reportedly came into money shortly before coming into contact with Bradley, such as an inheritance or casino prizes.

Court documents said Bradley tricked all four the same way, seeking their help to dig up gold and lead them into the wooded area.

Bradley then allegedly killed them and then stole their cars or cash.

“His modus operandi, if you will, he wanted to target individuals who had money and who had wealth,” NewsNation law and justice contributor Jennifer Coffindaffer said.

NewsNation reached out to Bradley’s defense attorney but has not yet heard back.

Bradley is scheduled to stand trial for Blake’s death in January.

The Associated Press contributed to this report.