Photo: National Center for Missing and Endangered

Makayla Winston

The man believed to be the boyfriend of the21-year-old pregnant Mississippi woman who vanishedlast Thursday and was found dead on Monday has been arrested in connection with her disappearance, PEOPLE confirms.

Terrence K. Sample, 33, was arrested on Monday night after he turned himself in, Holmes County Sheriff Willie March tells PEOPLE.

“He and his lawyer came in last night,” says March.

He was booked into the Holmes-Humphreys County Regional Correctional Facility Monday night where he remains held. He has yet to appear in court and has not yet entered a plea.

Makayla Winston

March said that Sample told police he does not know Winston. “He denied being her boyfriend,” he says.

Her family members say they believe he was her boyfriend,theClarion-Ledgerreports.

Sample’s attorney Richard Carter said his client should be released if there are no charges, theClarion-Ledgerreports.

Her body did not show obvious signs of trauma,March said, WLBT reports.

At the time, March said, “We think it could have been somebody who knew her.”

Her body was taken to the state crime lab to determine the cause and manner of death, March said, adding that authorities are still awaiting the results.

“The cell phone was cleaned up so we’re also doing an investigation on the cellular phone, trying to find out what was erased,” said March, WCSC reports.

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“I want to thank all the other law enforcement agencies who helped us with this crime that was committed in Holmes County,” says March. “I also want to thank all the citizens who showed their concern in helping us locate the young lady’s body.”

Police are still investigating.

Before Winston’s body was found, Winston’s mother was worried about her daughter, especially since she was due to give birth.

Winston was last seen leaving her home in Goodman at about 9 p.m. Thursday.

Sample’s lawyer did not immediately return PEOPLE’s calls for comment.

Anyone with information about the case is asked to call the Holmes County Crime Stoppers at (662) 834-0099.

source: people.com