The autopsy results match a confession by the 48-year-old woman's boyfriend, police said. The 42-year-old man, who has been arrested on suspicion of murder, told police he killed the woman in mid-March and cut her body in pieces.
He did not disclose a motive, though both are believed to have been drunk at the time. Both the victim and suspect had problems with alcohol abuse, police said.
"The suspect is no stranger to us," Braunschweig police spokesman Joachim Grande told German news agency DDP, which reported that the 42-year-old had been the subject of previous harassment and assault complaints.
A janitor found the woman's badly decomposed torso on Tuesday in the cellar of her apartment house after residents complained about maggots and a terrible smell. Police used search dogs to find the rest of the pieces of her body, which had been hidden in a second suitcase in a field about a kilometre from the apartment house.
Police identified the woman by her tattoos as Karin N., DDP reported. Her last name has not been disclosed.
In his confession, the woman's boyfriend told police she was lying on a sofa when he struck her on the head. Terrified of being discovered, he said he hacked off her head and legs in the bathroom and hid the pieces of her body in the two suitcases.