All defendants have been held for trial in the Piazza double murder case after a preliminary hearing during which prosecutors announced that the woman who gave the killers access to the upscale Northern Liberties apartment will plead guilty and cooperate against the others.

Katoya Jones, 25, in fact, testified this morning, identifying and implicating Will Hook, 40, the alleged mastermind of the June 27 botched robbery, and Donnell N. Murchison, 33, the man prosecutors allege was the main gunman in the deaths of party planner Rian Thal, 34, and friend Timothy Gilmore, 40.

Assistant District Attorney Jennifer Silber said Jones is the only of the defendants to agree to plead guilty - in her case, third-degree murder - and cooperate against the others.

It was erroneously reported here earlier that four others also planned to plead guilty.

But during the three-hour preliminary hearing before Philadelphia Municipal Court Judge David C. Shuter the packed courtroom heard detectives read statements from the four admitting their individual roles in the events leading up to the double murder.

Those who made statements to police were Murchison, Robert Keith, 27; Langdon Scott, 26 and Antonio Wright, 28.

Hook and Edward Daniels, 42, have not given statements to police and Hook's attorney, Christopher Warren yesterday cast doubt on the credibility of Jones and the others who gave statements.

"How many days did they keep Jones without sleep and without access to a lawyer?" Warren asked afterward, referring to Jones' testimony that she was questioned for two days by homicide detectives.

Jones said she decided to confess and testify after detectives showed her a photo of Thal's corpse, shot point-blank in the head.

"I felt bad for her," Jones testified. "I couldn't believe she was dead over something I was involved in."

Jones was led into court by deputies who walked her within feet of the other defendants.

As she settled nervously into the witness stand, Selber's co-prosecutor, Assistant District Attorney Carlos Vega, told defense attorneys for Jones' codefendants that she would plead guilty to two counts of murder.

Jones, 25, identified and pointed out Hook - the man she called "Pooh" and who is also known as Keith Epps and James Wilson - and said he was a longtime friend who called and asked if she would let some men into the Navona building.

Jones lived in a second-floor Navona apartment; Thal and Gilmore were found shot to death in the hall outside her seventh-floor unit.

Jones also identified Murchison as one of the men she let into the Navona building.

Police have alleged that Murchison was the lead gunman seen on the building's surveillance video shooting Thal and Gilmore.

Hook told Jones he believed there was $500,000 in cash in Thal's apartment, according to Jones.

"How much was your cut?" asked Vega.

"We never discussed a price but I wanted $50,000 to $60,000," Jones replied.

The plan almost immediately went awry, however, as Jones said she learned when she saw "a mass of cop cars" outside her apartment complex.

At a meeting later that night at a North Philadelphia bar, Jones said Hook was disgusted at what happened.

"He told me, 'They panicked, they were rookies. That's why you don't tell [n-word] how much money is involved,'" Jones testified.

Police found $100,000 in cash and four kilograms - more than eight pounds - of cocaine in Thal's apartment.

Although Thal's friends and families described her as a planner who thrived in the Center City party scene but did not use drugs, police have said she was involved in the drug scene and may have been storing drugs and case for major traffickers.

Contact Joseph A. Slobodzian at 215-854-2985 or jslobodzian@phillynews.com.