Police in Tennessee say a body found on Monday is that of missing heiress Eliza Fletcher.
The 34-year-old mother-of-two was a teacher in the area, and the granddaughter of a local billionaire.
She was abducted while jogging early on Friday morning near the University of Memphis campus.
Cleotha Abston - a 38-year-old man with a previous conviction for abduction - has been charged with kidnapping and murdering Ms Fletcher.
Her family issued a statement after the discovery of her body, saying they were "heartbroken and devastated".
"Liza was a such a joy to so many - her family, friends, colleagues, students, parents, members of her Second Presbyterian Church congregation, and everyone who knew her," they said.
"Now it's time to remember and celebrate how special she was and to support those who cared so much for her."
Well-known in the community, Ms Fletcher was the granddaughter of the late Joseph Orgill III, a billionaire local hardware magnate and philanthropist. His company is now reportedly worth over $3bn (£2.6bn) and employs more than 5,000 people.
Ms Fletcher worked as a junior kindergarten teacher at St Mary's Episcopal School instead of for the family business.
She vanished at around 04:00 local time on Friday. CCTV footage showed a man approaching her and getting into a physical confrontation, forcing Ms Fletcher into a black SUV, according to police documents.
She was reported missing after failing to return home on Friday after her early-morning run, and her family posted a $50,000 (£43,330) reward for information.
The Memphis Police Department said officers had found a body at around 17:07 on Monday but stressed no identification had been made.
On Tuesday, officers said the deceased "located yesterday in the 1600 block of Victor" had been identified as Eliza Fletcher.
Authorities later confirmed the body had been found in the rear of a vacant duplex apartment.
At the time of the body's discovery, Cleotha Abston, who was arrested on Saturday, had been charged with aggravated kidnapping and tampering with evidence.
Additional charges for him have now "been added for first-degree murder and first-degree murder in perpetration of kidnapping", police said in the update.
He was arrested after his DNA was detected on a pair of sandals found near where Ms Fletcher was last seen, according to an arrest affidavit.
Officers also found a vehicle at the address where he had been staying that matched CCTV footage of Ms Fletcher being forced into a similar car.
Video shows him spending over an hour cleaning his car after arriving at his brother's apartment complex just over three hours after Ms Fletcher was abducted.
According to court documents, a witness said Mr Abston had been behaving erratically and had used carpet cleaner on his car's interior. The unnamed source also said he had washed his clothes in his brother's sink.
He attempted to flee when US Marshals arrived at the residence but was captured, the affidavit said.
Mr Abston previously served nearly 20 years in prison for kidnapping a prominent Memphis attorney in 2000 at gunpoint. He was released in late 2020.