A man who is pleading not guilty to fatally stabbing a woman 37 times a quarter of a century ago not only admitted the crime to investigators many years later but gave them details which only someone who had been at the scene of the crime would have known, an inspector told a court yesterday.

Police Inspector Chris Pullicino explained that although 21 years had passed since the 1984 murder when the police questioned Salvatore Mangion in 2005, the details he provided them with made it obvious that he must have been there.

Mr Pullicino was testifying at the start of Mr Mangion's trial by jury, before Mr Justice Joseph Galea Debono, over the murder of Rosina Zammit, 54, in February 1984 in Safi. Mr Mangion is also charged with stealing cash and items from Ms Zammit's house.

Earlier this month, Mr Mangion claimed that he was not mentally fit to stand trial but another jury decided he was.

Mr Pullicino explained that in 2003 he had been assigned to investigate unsolved cases. In 2005 he received a tip-off that Mr Mangion could have been involved the murder of Ms.Zammit.

At first, Mr Mangion had categorically denied his involvement but had a sudden change of heart, saying he wanted to cooperate with the police in their investigations. In his statement to the police, Mr Mangion said he had been on the lookout for Ms Zammit and spoke to her often outside her house. On the day of the murder, he had watched Ms Zammit going to Mass and followed her home. He knocked on the door and when he walked in she started screaming. He placed the knife on her neck and then started hitting her in the neck and chest.

"I don't remember how many times I stabbed her but they were many," he told the police.

He said he ran into the bedroom and found €466 in a cabinet and two ceramic statuettes. He left and caught a bus to Zejtun where he dumped his bloodstained clothes and the knife into a reservoir.

He spent all the stolen money in Paceville later that day and paid for a taxi back home.

The knife which was his mother's was about 30cm long. He had taken it with him to kill Ms Zammit because he didn't want her to tell the police, adding he had not worn any gloves or a balaclava.

He had spoken to Ms Zammit several times in the two weeks prior to the incident and had almost become her friend.

In a second statement three days later, Mr Mangion confirmed what he had told the police and added that he had never entered Ms Zammit's house before except on the day he killed her.

Mr Pullicino said the details which Mr Mangion gave them 21 years after the murder corroborated the circumstantial evidence the investigators found on the scene of the crime, such as where Ms Zammit had been stabbed, that there was no electricity that day, that she had opened the front door for him and that he had only rummaged around in the first room of Ms Zammit's house.

He said Mr Mangion was calm during the interrogations and replied, in detail, to each and every question he was asked. These details had not been broadcast in the media and only a person who was involved could have known them, the police inspector said.

Court expert Anthony Abela Medici said Ms Zammit had deep cuts on her neck and a lot of blood on her head. The victim had 37 stab wounds in all. She had three cuts on her hands, three stab wounds on her back and 34 more stab wounds on the front, from her neck down to the groin.

This was confirmed by Marie Therese Camilleri Podesta and Paul Cuschieri, who carried out an autopsy on Ms Zammit. They found injuries to various vital organs including both lungs and her liver, which had been penetrated from both sides. She had also been hit in her private parts.

The trial continues this morning when the defence will make its case after the prosecution presented all its witnesses during yesterday's sitting.

Lawyer Leonard Caruana, from the Attorney General's office, is prosecuting while lawyer Simon Micallef Stafrace is appearing for Mr Mangion.