A double tragedy unfolded at a St. Paul townhouse Monday when police found a mother of three who had been slain in her own home and a teenage girl who had been sexually assaulted.

A suspect has been arrested in the sexual assault of the girl at the home in the Payne-Phalen neighborhood.

“[It is] one of the most disturbing and heartbreaking scenes we’ve seen in awhile,” police spokesman Steve Linders said at a news conference Monday night.

Family members and friends gathered outside the home and hugged one another. A minivan was towed from the scene.

A relative described the homicide victim, who has not been identified, as feisty, generous and loving “with a very big heart.”

Police initially called the Monday morning death suspicious but are now investigating it as a homicide. Linders said the teenager was not one of the slain woman’s children. Police believe the suspect was holding the teen against her will at the townhouse and that the suspect knew both victims.

It could be up to 10 to 12 days before authorities determine a cause of death, he said.

The suspect, a 33-year-old man from East St. Louis, Ill., was booked into the Ramsey County jail on suspicion of kidnapping and criminal sexual assault. He is a person of interest in the ongoing homicide investigation. The Star Tribune generally does not identify suspects until they’ve been charged.

Police were called around 7 a.m. Monday to a residence in the 1500 block of E. Jessamine Lane about a death. St. Paul Fire medics were called to the scene and pronounced the woman dead.

Police found the teenage girl, who was taken to a hospital.

Police have not released the woman’s name; relatives were still being notified.

The victim’s sister Krystal, who declined to give her last name until she could reach the rest of her family, said she had been working as a certified nursing assistant in a senior living facility.

‘A big heart’

The victim was a 39-year-old mother of three who grew up in New Orleans but had lived in the Twin Cities for more than 20 years and loved the neighborhood. She was living in the townhouse with her three children and served for a time as president of the residents’ association.

“She was very determined and strong-willed,” Krystal said. “When she decided she was going to do it, it was going to be done her way.”

Police confirmed that other people were inside the residence where the woman was found, Linders said.

Neighbors arrived home in the late morning and early afternoon to find much of the area still taped off.

“It was extremely unsettling,” said Kerri LeTexier. She said the neighborhood is quiet, with some police activity from time to time.

“Nothing at all like this,” she said. “We don’t know who it was but it’s pretty sad.”