An Italian couple have confessed to killing four neighbours in a dramatic twist to a murder mystery that has gripped Italy, prosecutors say.
Raffaella Castagna, her two-year-old son, mother and a friend were found on 11 December with their throats slit.
Italian papers blamed Ms Castagna's Tunisian husband, recently released from jail, but had to eat their words when he proved he was abroad.
Now prosecutors believe the cause of the massacre was a feud over noise.
Olindo Romano and Rosa Bazzi - the couple arrested in the case - had complained in the past to their neighbours about noise levels, Italian media said.
It was reported that the couples, who lived in neighbouring flats in a block in Erba, northern Italy, had come to blows on 31 December 2005, after which Ms Castagna proceeded to sue her neighbours.
Investigators said on Thursday that Mr Romano and Ms Bazzi - an apparently respectable middle-aged couple - had confessed to settling the dispute in the most violent way.
The apartment was gutted by fire after the killings
The bodies were found in Ms Castagna's apartment, which had been set on fire.
During a 10-hour interrogation, investigators said, Ms Bazzi said she had killed two-year-old Youssef because he was crying.
Following the murders several Italian newspapers issued rare front-page apologies after accusing Ms Castagna's husband, Azouz Marzouk, of the crime.
He had been released from prison under a mass pardon shortly before, but was on a trip to his Tunisian homeland at the time of the killings.
Papers speculated the attacks may have been related to his drug-dealing past, before that theory was apparently scotched by the neighbours' confession.