A 23-year-old woman on Monday pleaded not guilty in the slaying of a local businessman, and a competency evaluation was ordered for one of her co-defendants.

During an arraignment hearing in Suffolk Circuit Court, Naomi Nichelle Lambert calmly replied “not guilty” after each of her five charges was read aloud: first-degree murder, conspiracy to commit robbery, attempted robbery and two counts of use of a firearm in the commission of a felony.

“Do you understand what you are being charged with?” Chief Judge Carl Edward Eason Jr. asked Lambert.

“Yes, sir,” she replied.

Lambert opted for a jury trial. She had no questions for Eason.

Katron Walker, 32, and Leon Jerome Hayes, 34, both face identical charges as Lambert, as well as possessing a gun while a convicted felon.

The trio was indicted this month in the Sept. 22 murder of Donald Carter. The commonwealth alleges Walker, Hayes and Lambert murdered the 82-year-old during a botched robbery outside his East Washington Street furniture store.

At a preliminary hearing Dec. 2, a prosecution witness testified she was with Lambert that night, and the alleged crime was set up using Carter’s office phone minutes before he was killed.

According to the witness, A’unique White, Carter picked her up, along with Lambert and another female friend, after driving past them in his car.

Cater took them back to his store and offered to pay for sex, according to White, and Hayes and Walker, coordinating with Lambert after she asked to use Carter’s phone, waited outside to rob him.

After a 911 call about 1:12 a.m. that day, Carter was found near his business, suffering a fatal gunshot wound to the lower torso. He died shortly after arriving at Sentara Obici Hospital by ambulance.

Before Lambert’s not-guilty pleas Monday, Eason ordered Walker to undergo a mental evaluation in the next 45 days.

Walker’s attorney, Lori Butts, requested the evaluation. “I have represented (Walker) in the past, and I know some of his mental status,” Butts said.

“The current matters, there have been some concerns that I do have, and wish to have him evaluated for competency.”

Butts also said she has filed a motion for a change of venue; she did not say why.

Eason said that motion, and any others, would be addressed once Walker’s competency is established.

Lambert’s trial, expected to run three days, is set to begin March 16.

Hayes’ arraignment is set for Feb. 20.