ANDOVER — A man arrested in the death of an 18-year-old Minnesota woman he had apparently hired as a prostitute through an online ad before killing her also is wanted for three attacks on escorts in Georgia, authorities said Thursday.

The 23-year-old man was in custody Thursday in Anoka County on suspicion of the murder of Brittany Clardy, of St. Paul, and is expected to be formally charged Friday.

Anoka County Sheriff’s Cmdr. Paul Sommer said the suspect has “made some admissions.” He did not elaborate.

Clardy’s body was found Feb. 21 hidden in her mother’s car in a Columbia Heights impound lot, eight days after the car had been towed from nearby Brooklyn Park. Clardy left her parents’ home Feb. 11 to go to a store but never returned. Authorities have been tight-lipped about details surrounding her death but released some information Thursday as they announced the arrest.

Sommer said Clardy was working as a prostitute and had been posting ads on a website for a number of months. Her parents did not know that she was an escort, but others close to her did, he said.

Sommer said the Minnesota case began as a missing person investigation in St. Paul. He said surveillance video shows Clardy went to the store as planned. But she never came home.

After Clardy’s mother’s car was impounded, officials informed her via a letter. St. Paul police went to the lot and discovered Clardy’s body. Authorities have not released her cause of death.

Police also found several prepaid cellphones in the car and used them to narrow a list of suspects, including Clardy’s potential clients.

Authorities in Chamblee, Ga., said the man being held in Minnesota is wanted in three assaults there. Chamblee police Sgt. Ernesto Ford said he believes there may be more victims.

“You don’t just turn into a sadistic psychopath overnight,” Ford said. “This has been going on for quite a while.”

Ford said authorities in Georgia plan to bring the man there to face charges. Ford said he’s a suspect in three separate attacks in Chamblee, one in September and two in December. In all three attacks, a man hired women for sex off of a website, and the women went to his apartment where they had consensual sex, Ford said. But after the man paid the women, he began assaulting them before they escaped.

One woman was held captive and repeatedly raped and beaten for 36 hours. Ford said the woman was tied up, gagged, and stuffed in a storage bin in a car before she escaped. He said the suspect had an accomplice in that attack. That man is still at large.