The mystery surrounding the discovery this week of an unknown woman’s body near the Bonnet Carre Spillway deepened Thursday as authorities announced she was probably the victim of a homicide.

A CN Railroad work crew spotted the body in Lake Pontchartrain just west of the entrance canal to the lower section of the spillway near Norco about 7 a.m. Wednesday, according to the St. Charles Parish Sheriff’s Office.

Investigators believe she was killed and that her body may have been dumped from Interstate 10.

The Sheriff’s Office said a forensic autopsy had determined that the victim likely had been in the water for two to three days. Sheriff Greg Champagne said investigators are asking for the public’s help in identifying her.

Officials have not released any details on how she may have died.

The classification of the woman’s death as a homicide means St. Charles has recorded three killings in less than two weeks — an alarming pace for the sparsely populated parish.

In a recent case in the parish with one striking similarity, the body of 16-year-old Kenner girl Jorion White was discovered dumped in a drainage ditch in St. Rose on April 24. A suspect in that killing, the boyfriend of White’s mother, was arrested Monday.

“We don’t see any reason to believe that those two are connected at all,” Champagne said. “They basically have no connection to St. Charles Parish, other than the fact that bodies were dumped here.”

The victim, whose body was found near the Bonnet Carre Spillway, was a black woman 45 to 60 years old, approximately 5 feet 6 inches tall and 180 pounds, according to the Sheriff’s Office. She was found wearing a red and white plaid button-down shirt, a white undershirt and a blue sports bra.

An autopsy revealed that she had no remaining natural teeth. She had gold-capped dentures on the top of her mouth but no lower dentures when she was discovered.

The woman had no scars or tattoos, but she had undergone a full hysterectomy, a fact Champagne said investigators released in the hope that “somebody will help us identify her.”

Anyone with information that might help the Sheriff’s Office identify the woman is asked to call Detective Chris Baird or Lt. Derek Pertuis at (985) 783-1135 or (985) 783-6807, or Crimestoppers at (877) 903-7867.