A Philly man will be charged in the 2005 killing of a woman found decapitated in the Puget Sound near Seattle

A financial professional living in North Philadelphia has been taken into custody and is expected to be charged in the 2005 murder of a woman whose decomposed and headless body was found floating in the Puget Sound near Seattle, authorities said.

The killing of 33-year-old Shanan Lynn Read had stymied investigators for years — with relatives wondering if she had been poisoned or intentionally given a lethal dose of drugs before her remains were discarded in the inlet connected to the Pacific Ocean.

But authorities in Kitsap County, Washington announced Thursday that Brian Bourquard, 39 — who’d been living in a brick rowhouse in Philadelphia on the 700 block of Master Street — was part of a group of men who threatened Read and then fatally beat her with a metal baton inside a Seattle apartment, apparently over a debt. The men then put Read’s body into a Rubbermaid container, authorities said, took it to Bourquard’s family cabin more than an hour away, stored it there for weeks, doused it with chemicals to speed up its decomposition, and eventually shoved the Rubbermaid into the sound.

Bourquard — who, according to his LinkedIn profile was a vice president of strategy and finance at a robotics company and held a Ph.D in agricultural economics — was arrested Monday in Philadelphia to await extradition to Washington. An attorney listed for Bourquard in court documents did not respond to a request for comment late Thursday, and attempts to reach relatives were not successful.

Two of Bourquard’s accused coconspirators were taken into custody Tuesday in Florida and California, the Kitsap County Sheriff’s Office said. Another is deceased.

The office called Read’s killing “brutal” and said the investigation that led to her accused killers’ arrests was “far reaching and exhaustive.”

Attempts to reach Read’s relatives late Thursday were not successful.

Charging documents offer a glimpse of what police believe happened in the crime, and detail how Bourquard’s own journal entries helped build a case against him.

Still, many questions remain, including how and why authorities decided to charge Bourquard now — 17 years after Read’s death.

The statement of probable cause for his arrest gave the following account:

The killing occurred in August 2005 in Seattle. Read, Bourquard, and at least two other men were involved in a theft ring, sometimes forging financial documents together. But the men thought Read had stolen from them, so Bourquard and another man, Anthony Martinez, began threatening her inside an apartment.

Martinez then beat Read in the head with a metal baton. When she fell unconscious, no one checked her vital signs or tried to help her.

Another coconspirator, Brandon Reeve, would later tell police that Read “could have been alive” after the assault. But Bourquard and another man — Oscar Gonzales — put her body into a Rubbermaid-style container, drove the container to Bourquard’s family cabin in Port Orchard, and left it in the fireplace.

Reeve, meanwhile, stayed at the apartment, putting evidence into trash bags and wiping surfaces for fingerprints or DNA.

Two weeks after the murder, Bourquard and Reeve returned to the Port Orchard cabin to pour chemicals, including lye, on Read’s remains in an attempt to speed up its decomposition.

And in January 2006, Bourquard took another man, Michael Thomasan, to the cabin to help push the container into the sound.

On Jan. 15 of that year, Read’s headless torso was found floating in the plastic container in the water. Her head washed ashore two months later.

Authorities had been investigating the possibility that Read had been murdered since at least 2008. A witness told police she had been poisoned in Seattle before being driven to Kitsap County. But investigators at the time were not given permission to search Bourquard’s cabin, according to a Seattle Times account, and the apartment where Read was beaten had been cleaned of any sign of the crime.

In the statement of probable cause for Bourquard’s arrest, prosecutors say journal entries he wrote show he’d had planned Read’s killing weeks in advance. It was not clear when or how authorities discovered the journals. But in them, prosecutors said, Bourquard threatened Read and her children, and “also expressed violent/murder ideations to other people who felt he double-crossed him.”

In one entry, from August 2005, prosecutors said Bourquard wrote: “Shanan owes $4,000 to some people. Unless she has it by Sunday, her daughter is dead and Anthony could lose his position. All because Shanan [expletive] off all the money. Where is the [expletive]? She put it all on the line and now we’re all going to burn unless we see a miracle. Do we all die if Shanan doesn’t get the money.”

In another entry, which prosecutors said was undated, Bourquard wrote in part: “The effort required to kill somebody is all gone, removed from the equation.”

And in another undated entry, prosecutors said, Bourquard wrote: “Straight killer ... don’t put it past me, but you won’t see it coming.”

Bourquard was taken into custody in Philadelphia on Monday and was being held without bail to await extradition to Washington. He is expected to face first-degree murder charges, police said.

Gonzales, accused of helping Bourquard drive Read’s body to the cabin, was arrested Tuesday in Riverside, Calif., and also will face charges of first-degree murder.

Reeve, arrested Tuesday in Sarasota, Fla., will face second-degree murder charges for cleaning the apartment and helping douse Read’s body, among other actions, authorities said.

Martinez, who allegedly beat Read with the metal baton, is now dead, police said.

It was not clear Thursday how quickly Bourquard might be extradited. Court records say he is due back before a city judge next week.

Staff Writer Robert Moran contributed to this article.