MAYS LANDING, N.J. - The Atlantic County couple accused of killing a tourist following a carjacking and robbery pleaded not guilty to first degree homicide Wednesday as authorities continued to gather evidence in what is emerging as a week-long crime spree.

Atlantic County Superior Court Judge Michael Donio set bail at $2 million apiece for Craig Arno, 44, and Jessica Kisby, 24, after each entered not guilty pleas to murder charges that were filed last week.

Neither defendant said much during brief appearances before the judge.

They are accused in the stabbing death of Martin Caballero, 47, who was kidnapped on May 21 from a parking garage at the Trump Taj Mahal Casino Resort.

During Wednesday's hearing, authorities disclosed that Kisby had been transferred to the Salem County Jail to keep her from communicating with Arno.

And after the hearing, Atlantic County Prosecutor Theodore Housel detailed additional charges that have been filed against the pair.

Arno had been charged with armed robbery for an alleged holdup at a Dunkin' Donuts in Hamilton Township on May 20, one day before the alleged carjacking-murder occurred, Housel said.

And Arno and Kisby have been charged in Atlantic City with the theft of a van from a condo parking garage on May 26, two days before they were arrested in the carjacking case.

The prosecutor provided few additional details about those charges.

The couple had previously been charged with the robbery of a K-Mart in Pleasantville on May 24.

Kisby, an Egg Harbor Township resident with a five-year-old daughter, said little during her appearance Wednesday.

A thin woman with long, black hair, she appeared in court handcuffed and shackled at the ankles and dressed in a green prison jump suit.

Her mother and an aunt sat in the second row of the courtroom, but she did not appear to make eye contact with them. The women met briefly with her lawyer, Steven Scheffler, after the hearing, but declined to comment as they left the courthouse.

Scheffler described the two women as "shell shocked" by the charges, but said he was happy to see family members had turned out to support his client.

He said he was still gathering information about the prosecution's theory of the case, adding, "It just doesn't make sense from a big-picture perspective."

Arno, dressed in a black-and-white, jail-issued jump suit, said "yes" when Donio asked if he understood the charges against him, then entered a not guilty plea through his attorney, public defender Eric Shenkus.

Formerly of Philadelphia but living in Atlantic City at the time of the carjacking, Arno has an extensive arrest record for bank and credit card fraud and has spent several years in jail for those charges.

His first brush with the law came at age 16, when he was charged with homicide in a drag racing accident on City Avenue. His car struck another vehicle, killing a nurse who was driving to work. The charge was later downgraded to manslaughter and he was sentenced to five years' probation.

Arno and Kisby apparently met while inmates at the Atlantic County Jail in February where they were serving time on unrelated charges. They were released sometime in March and apparently developed a relationship as well as a criminal partnership.

What led them to the parking garage and the confrontation with Caballero on May 21 is still unknown.

One investigator described it as a random act, a "robbery gone bad."

Caballero, 47, had arrived at the casino that night with his wife. They planned to celebrate his daughter's 22nd birthday with other family members.

Authorities said Arno and Kisby carjacked and kidnapped Caballero after accosting him in the garage around 10:30 p.m. His car, a Lincoln MKS, was discovered about three hours later on fire in Gloucester Township, Camden County.

His ATM card had been used to withdraw $300 and had also been used to purchase fire starter and five gallons of gasoline that night, authorities said.

Caballero, a grocery store manager from Hudson County, was reported missing by his family when he failed to return to the casino from parking the car. His badly decomposed body was found by the side of a farm road in Atlantic County on May 30.

He had been stabbed multiple times, authorities said.

Arno and Kisby were arrested at a motel outside of Atlantic City on May 28 following an intense investigation by the Atlantic County Prosecutor's Office and the Atlantic City Police.

Originally charged with kidnapping and carjacking, they faced murder charges after authorities got a positive identification on Caballero's body late last week.

At the time of his arrest, Arno had burns on his chest and right hand. Authorities said he and Kisby had stolen bandages and other medication from a K-Mart in Pleasantville on May 24 in order to treat his burns.

Housel offered few new details about the case Wednesday, but during the hearing for Kisby he told Donio that she was moved from the Atlantic County Jail after authorities there learned that she was trying to communicate with Arno through other inmates.

The system, known as "kiting," is a way for inmates to overcome prison regulations that limit communication between prisoners, particularly co-defendants in a pending case.

Housel said jail officials had seized a letter in which Kisby detailed her plan.

Donio, responding to an objection raised by Kisby's lawyer, said he would review the letter in private to determine whether the transfer was warranted.

Scheffler said it was difficult for him to meet with his client in Salem County, which is more than an hour's drive from his office.

Contact staff writer George Anastasia at 856-779-3846 or ganastasia@phillynews.com.