Sandra González, found murdered at her Coll d'en Rabassa home on Thursday morning, was beaten about the head with a hammer and strangled. The autopsy revealed that she died as a result of the head injuries and asphyxiation, but according to judicial sources, forensics have been unable to establish whether the 22-year-old waitress was first attacked with the hammer or strangled. The prime suspect in the murder case is her 25-year-old boyfriend, Alberto Lopez. He was still under police guard in the secure wing of Palma's General Hospital yesterday where he was being treated for self-inflicted wounds after he tried to slash his wrists following the murder. The judge in charge of the case is today expected to make a decision as to whether he will hold the preliminary hearing at the hospital or in court. The victim's parents, especially the mother, who suffered a nervous breakdown on Thursday, were being comforted by friends and family yesterday while detectives were still trying to piece together events leading up to the murder. Officers believe that the suspect spent most of Wednesday night nearby where the body lay in the flat the couple shared. Alberto Lopez is said to have had problems in the past with drugs and alcohol, but police sources said that some of the people questioned have suggested that the 25-year-old builder was still addicted to drugs; leading police, at this stage, to suspect that the young couple had been arguing over money. The judge yesterday ordered samples of Alberto Lopez's blood to be taken in order to establish if he was under the influence of drugs at the time of the murder. Apart from the distress which has been caused to friends and family, the murder has also outraged the Majorca women's rights group, Lobby de Dones. Last night they held a rally in Palma in protest over this latest case of domestic violence. The organisation said that this crime is particularly concerning because of the age of the couple involved. Domestic violence dominated the news across the country last year, with a number of media campaigns and television marathons being held to increase the public's awareness, raise funds for the high number of victims and try to reduce the number of incidents. At last night's rally, protesters called on all the public administration to adopt effective measures to bring an end to the death, torture and suffering of so many women. The organisation is also thinking about taking its own legal action in the case against the killer of Sandra Gonzalez.