GREENFIELD — He planned to subdue them, tie them up and take off with their vehicle and valuables — or sneak away before they noticed — but the robbery quickly turned into a double homicide.

At the Rockbridge County, Va., Sheriff’s Department, Joshua Hart, 25, of Athol, confessed to the murder of Orange resident Thomas Harty, 95, and the fatal wounding of his wife, Joanna Fisher, 77.

Days prior, on Oct. 5, 2016, Hart and his co-defendant Brittany Smith, 29, of Athol, had allegedly fled from the couple’s 581 East River St. home in Orange, having stolen their Toyota Matrix and credit cards and disabled their telephones to prevent Fisher from calling for help. Hart and Smith have pleaded not guilty to all charges.

The audio recording of Hart’s confession was played for the 14-person jury and Judge John Agostini at the Franklin County Justice Center on Tuesday, the third day of Hart’s Superior Court trial.

“We were going to go in, grab the car, purse and get away before they knew anything happened, because they were old,” Hart is heard saying, speaking with Capt. Tony McFaddin and Lt. Steven Funkhouser of the Rockbridge County Sheriff’s Office.

“It didn’t happen that way,” Hart said.

Hart and Smith were tracked to Virginia by the Massachusetts State Police, who monitored cellphone tower signals for clues of the pair’s whereabouts. A photo was distributed to local police and a Lexington, Va., Walmart, where an employee recognized Hart as a customer in the store.

She flagged down nearby police, and Hart and Smith were apprehended in the parking lot as fugitives.

When Hart was processed and taken to a holding cell, he told police he wanted to talk.

“Hart wanted to speak with us,” said McFaddin, who testified and remained on the witness stand while prosecutor Jeremy Bucci, chief trial counsel for the Northwestern District Attorney’s Office, played the tape recording.

At the beginning of the interview, Hart waived his right to remain silent or have an attorney, and indicated he understood his Miranda rights by reciting them himself. He then plunged into his version of the story.

“There was a knife on the counter,” said Hart, calmly recalling his entrance into Harty and Fisher’s home. “I ended up stabbing him and just didn’t stop. Brittany was still outside at first.”

Hart explained that Smith and he had been “geeking and stuff, like we didn’t know what we were going to do,” after being arrested two nights before the home invasion for car theft.

The prosecution alleges that Hart, who had arrest warrants from Pennsylvania, and Smith, a heroin addict, wanted to steal a car and run away together to avoid incarceration or court-ordered drug addiction treatment, respectively, due to their arrests for the car theft. According to Hart’s own words in the taped interview, the prosecutors are correct.

Hart’s account of what happened in the house is where he differs with the prosecution. The prosecution has described the murders as a “joint venture,” but Hart frequently downplayed Smith’s role in the attack throughout the interview.

“Brittany was still outside at first,” Hart said. “(When she came in) she just froze.”

Hart said he began attacking Harty before Smith’s entrance into the house, and that he solely attacked Fisher while Smith stood by — Fisher herself stated to police and family that her attacker was female before her death about a month after the attack.

“I ended up stabbing her, too, but I couldn’t finish it,” Hart said of Fisher, who used a wheelchair because of partial paralysis from a spinal stroke.

According to Hart, Harty was seated in a chair in the living room, but got up when he saw Hart in his home.

“He started getting up and yelling which obviously freaked me out because I couldn’t have him yelling,” Hart said.

Hart said Harty was more physically imposing up close than he first realized when spying on the couple through the windows of their home. He also said pictures in the house of Harty hiking at a very old age made him nervous about the man’s athleticism.

“He started coming toward me. As you can see, I’m a small guy,” Hart said. “I don’t know what I was thinking at the time.”

Funkhouser questioned Hart, who stated he had never killed anybody before Harty. He said he stabbed the man “six times, maybe more,” rather than flee when Harty came toward him.

“You had an opportunity to retreat, to leave the home you broke into,” Funkhouser said. “That didn’t ever cross your mind?”

“I don’t think anything crossed my mind,” said Hart, who reiterated his desire to avoid incarceration.

“I didn’t want him to die, but I couldn’t have him attacking me,” Hart said.

Hart said the rosary beads around his neck were ripped off by Harty — some of those beads were found at the crime scene near Harty’s body — and that he forced Harty back into his chair, repeatedly stabbed him and held a pillow over his face until he stopped breathing.

“I didn’t want him suffering,” Hart said.

When asked what he believed he deserves for his actions, Hart said “I deserve whatever I get.”

“I shouldn’t get out,” he added.

“You think you shouldn’t get out in your lifetime?” Funkhouser asked.

“Definitely not,” Hart said.

Funkhouser was skeptical of the minimal role Smith played in Hart’s account, questioning why Smith would initially be waiting outside, not doing anything, while she heard screaming, yelling and Hart stabbing Harty. But Hart was insistent.

“She has a 2-year-old. I brought her into… dragged her into this nightmare,” Hart said.

Hart repeatedly professed his desire to “cut a deal” to help Smith, “because she didn’t have anything to do with this.”

He professed his love for Smith, saying when he first started dating her a couple months before the attack, he felt like they “knew each other forever.”

After the interview, Hart provided the Virginia police with a written confession.

Hart’s defense attorney, Brian E. Murphy, has said that Smith is in fact responsible for both of the murders, and that Hart helped her steal from the couple, “clean up” and run away. According to Murphy, Hart was “madly in love” with Smith, and his confession to Virginia police was false, and given in order to protect her.

“It’s safe to say during this interview that Hart’s reason to talk about this was to help Ms. Smith?” Murphy asked McFaddin in cross examination.

“Yes,” McFaddin said.

Smith will be tried after the conclusion of Hart’s case. Agostini said Tuesday he expects the jury to begin its deliberations on Hart’s case on Friday at the latest.