Student's grotesque killing is still clouded in mystery

After the apparent breakthrough, the contradictions, retractions and allegations. Perugia was awash with rumour and recrimination last night after fresh details emerged of crucial evidence that led Italian police to declare the case of murdered British student Meredith Kercher closed.

The three suspects – the English student's 20-year-old flatmate Amanda Knox, her Italian boyfriend Raffaele Sollecito and Congolese bar owner Diya "Patrick" Lumumba – were being held in solitary confinement in Perugia's jail after the apparent crumbling of the American during an early morning interrogation.

Italian newspapers carried blow-by-blow accounts of how the blonde, expensively educated student gave police the break they were looking for shortly before dawn on Tuesday when she admitted that, contrary to what she had claimed for days, she had been in the flat on the night of Ms Kercher's murder. Her evidence places all four actors at the scene of the crime during the vital hours. What is more, according to police accounts of her interrogation, Ms Knox said she had heard screams coming from her flatmate's bedroom – but claimed to have covered her ears to block out the noise.

"That evening," she told police, "we wanted to have some fun. We invited her [Ms Kercher] to join in, too. Diya wanted her..."

She told police that on the night of Thursday, 1 November, she met Mr Lumumba at around 9.30pm in the middle of Perugia after exchanging text messages with him. Contradicting her earlier claims that she had spent the night away from her flat with Mr Sollecito, she said: "Then we went to my house. I don't remember exactly if my friend Meredith was already at home or if she joined us later. What I can say is that Patrick and Meredith went together into Meredith's room while I think I stayed in the kitchen.

"I can't remember how long they stayed together in the room, I can only say that at a certain point I heard Meredith scream and I put my hands over my ears because I was scared. I don't remember any more, there is a great confusion in my head. I don't remember if Meredith screamed or if I also heard thuds because I was so upset but I think so. I'm not sure if Raffaele was present that evening but I remember clearly waking up in my boyfriend's house, in his bed, and that we went back to my home in the morning where I found the door of the apartment open..."

In what was evidently for her a tense, desperate interrogation – "she repeatedly brought her hands to her head and shook it," the police noted impassively – Ms Knox shed some much-needed light on the case. But, despite the initial excitement among the media and dramatic declaration by police that the case "was closed", her confession raised as many questions as it answered.

Italian police took enormous liberties by explaining, in a press conference just hours after that early morning interview, how Ms Kercher was killed in a "sexual attack" in which all three of her "friends" were involved. The admission of Ms Knox, published verbatim in Italian papers, takes us only a fraction of that distance. In fact, the first real breakthrough in the investigation came on Monday night when Mr Sollecito, Ms Knox's boyfriend of two weeks' standing, admitted to police that he had previously told them "a load of shit" because "Amanda had convinced me of her version of events and I hadn't thought about the inconsistencies".

Despite this admission, however, Mr Sollecito has yet to shift an inch on crucial matters: he still insists he spent the night at his own home. And Mr Lumumba, fingered by Ms Knox as the man who killed Ms Kercher has yet to be interviewed by police at all. The jigsaw is only half completed. Diya Lumumba is a well-known figure in Perugia student circles. He has run a bar called Le Chic there for 10 years. Ms Knox earned casual money distributing flyers for the club, and apparently Ms Kercher hoped to work for him, too. After the murder, but long before his arrest, Mr Lumumba told a local paper: "She was a really nice girl. When she came into my bar the first time, she asked me for a vodka. We immediately became friends, and she was going to hand out flyers at my venue. She would have been ideal as she knew so many people and had so many friends. She made friends really easily."

Perugia police chief Arturo di Felice says all three suspects will be charged with complicity in forced sex and aggravated homicide. But none has been charged yet. Tomorrow they will appear before a judge who is expected to confirm the validity of their detention. Police are now hoping that some days of solitary confinement – in ignorance of what the others have revealed – will induce all three of them to bring some clarity to what police yesterday called "this chaos of declarations".

But if it doesn't there is still a host of forensic evidence left in Ms Kercher's bedroom which may help fill the gaps. They include prints of shoes, which police say could belong to Mr Sollecito, and bruises on Ms Kercher's body. The knife marks on the wound to her throat that killed her could have come from a kitchen knife also belonging to Mr Sollecito.

Meanwhile the grieving Kercher family were in Perugia, her father, John, mother, Arline, and sister Stephanie, hoping to be allowed to take Ms Kercher's body back home. Stephanie, 24, said in a statement that she read out to journalists: "Nothing can prepare you for the news we received on Friday evening... [Meredith] was one of the most beautiful, intelligent, witty and caring people you could hope to meet... a loving daughter and sister and a loyal friend."

Last night Ms Knox's mother, Edda Dellas, from Seattle where her husband is a vice-president of Macy's department store, arrived in the Umbrian capital. She had flown to Italy to comfort her daughter after learning that her flatmate had been slain. She was informed of her daughter's arrest on the flight over.