Here’s what investigators said about the South Carolina murder of Mass. native Celia Sweeney
Mark Dwayne Walton, 36, has been charged with accessory after the fact of murder.

Mark Dwayne Walton.
The body of Celia Sweeney, a Massachusetts native who went missing in South Carolina late last week, was found inside a black container left in the woods some 200 miles from her Charleston apartment, according to court filings.
The detail is one of several shedding new light on the 28-year-old’s death that emerged after Charleston police announced Wednesday the arrest of Mark Dwayne Walton, 36, who’s charged with accessory after the fact of murder.
Walton appeared in Charleston County Bond Court, where a judge set a $500,000 surety bond.
The arrest is the only one authorities have made since Sweeney’s body was discovered Monday on the property of an Inman residence — the home of 32-year-old Buddy Allen Carr, a person of interest in her disappearance who was also found dead at the scene, police say.
Sweeney was reportedly a Scituate native and moved south about a year ago. The Spartanburg County Coroner’s Office ruled her death a homicide.
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In an affidavit obtained by Boston.com, authorities say their investigation began the night of Friday, Feb. 28, after Sweeney failed to respond to calls and texts from her boyfriend, who also found blood in her apartment.
She did not appear for work that day at King Street Grill, either, her friends told police later. It was unlike her, they said.
And her 2010 Audi S5 was nowhere to be found.
Authorities found ‘a significant amount of blood’ at Sweeney’s apartment

Celia Sweeney.
Sweeney’s boyfriend, who was not identified, had left his home to check on Sweeney, who lived alone, when he couldn’t get in contact with her, Charleston police Det. Joseph Owens wrote in the affidavit.
At her apartment, he found “a significant amount of blood” throughout the home, but not Sweeney, according to the filing.
Police got involved when they were dispatched at his request to conduct a welfare check around 8:52 p.m. Friday and obtained a search warrant for the apartment.
“The analysis yielded evidence that someone likely sustained fatal injuries as there was a significant amount of blood throughout the apartment and signs of a struggle,” Owens wrote.
Authorities did not find Sweeney’s cellphone but used a ping to show its last known location was “in the general area of her apartment” earlier that day around 11:30 a.m., he wrote.
“The forensic processing also yielded bloody footprints yielding a possible band name and tread pattern of a boot,” Owens wrote. “A single cartridge casing was located in the living room of the apartment.”
According to Owens, detectives spoke with Sweeney’s friends, including a neighbor who said she was with Sweeney and two men the night before: Walton and another man whose name was redacted in the document.
The group went to several restaurants and bars before returning to Sweeney’s apartment, Owens said, adding that police know Walton “was in and out of Sweeney’s apartment” over the course of the following two hours.
Phone records of Sweeney’s last known communication, just before 3 a.m. on Feb. 28, show she was frustrated about a person “being left alone” in her home and that she would attempt to remove the individual, Owens said.
The records indicate there were multiple, unsuccessful attempts to reach Sweeney after that point in time, he wrote.
Carr’s body was found with a ‘self-inflicted gunshot wound,’ documents say

Buddy Allen Carr.
On Saturday, Feb. 29, police found Sweeney’s Audi convertible about a half-mile away from her apartment, according to Owens.
Witnesses told police they saw the car enter a parking lot ahead of a white, 2019 Ford F-150 pickup truck around 6 a.m. on Feb. 28, the affidavit says. The driver of the Audi then entered the truck, and the Ford left the lot, police said.
Authorities were able to track the movements of the pickup truck during the investigation and discovered it was driven into the West Ashley area of Charleston on Interstate 526 later that morning, with a black container in its bed.
The investigation traced the F-150 to Carr’s residence in Spartanburg County, according to filings.
With a search warrant in hand, authorities found Carr dead “with an apparent self-inflicted gunshot wound” inside his home, Owens wrote.
Police also found a black Husky container approximately 20 yards from the pickup truck, “consistent with the one observed in the bed of … (the) pick-up truck,” Owens wrote.
Inside the container, authorities found Sweeney’s body.
“Sweeney suffered significant blunt force trauma to her head which likely resulted in her immediate death,” the affidavit says.
Inside the truck, police found a claw hammer with a red substance that tested presumptive for blood, Owens wrote. Authorities also found latex gloves, concrete bags, and camouflage nylon straps, he said.
Inside the home, investigators also discovered a Home Depot receipt showing cleaning materials and multiple bags of concrete were purchased on the afternoon of Feb. 28. In addition, a 45-gallon Husky container was purchased separately at the store that day, and store surveillance video footage showed Walton was present for that purchase, according to the affidavit.
Walton, a Charleston resident, was charged “based on the fact that (he) was present at the time when those items were purchased and the fact that these items were used in the concealment and disposal of Sweeney’s body,” Owens wrote.
Should he post his bond, Walton must have no contact with Sweeney’s family “verbally, electronically, on social media, or by third party,” a court case index shows. He is due back in court on May 8.
Sweeney’s mother tearily spoke before the court Wednesday, WCSC reports.
“There’s emptiness in me that only Celia could fill,” she said.”I will never get to embrace my daughter again.”
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