'Cannibal killer' Matthew Williams who murdered Cerys Marie Yemm 'not properly managed after prison release'
The mother of a man believed to have murdered a woman in an act of cannibalism has said her son "should have been in hospital".
Cerys Marie Yemm, 22, died from her injuries at Sirhowy Arms Hotel, a homeless hostel in Argoed, Blackwood, south Wales, in the early hours of Thursday morning.
Her attacker, Matthew Williams, who had recently been released from prison, also died at the scene shortly after police discharged a 50,000-volt Taser and arrested him.
The Government is to examine whether 34-year-old Williams was properly managed following his release from prison.
His mother Sally Ann told the BBC he had been a regular drug taker, suffered paranoid schizophrenia and refused her request for him to see a doctor.
"He would see things that were not there, he would hear voices, say food was trying to poison him and he would hallucinate. He was aggressive to people he thought were a threat to him," she told the broadcaster.
"He should have been in hospital. Every time he came out of prison, we'd go through the same process. He'd be placed in a hostel somewhere with very little supervision and no psychiatric help outside."
She added the last time she saw him was the day before the attack, when he was "troubled but not desperate", and they had arranged to meet the next day.
Meanwhile, South Wales Police has launched a murder investigation after the deaths and the Independent Police Complaints Commission (IPCC) will also probe the incident.
A spokesman for the Ministry of Justice confirmed a serious further offence review will take place to see if lessons can be learned from the case.
Such reviews are immediately launched if a serious offence is alleged to have happened within 30 days of a person leaving prison or is on licence.
The review will examine the circumstances of Miss Yemm's death, the management of Williams following his release and whether steps can be taken to improve public protection.
Welsh Assembly member William Graham has led calls for an inquiry into reports Williams was not monitored upon his release from prison.
"It is now clear that Mr Williams posed a risk to the public and I am extremely concerned that monitoring appears to have been deemed unnecessary," Mr Graham told the BBC.
"If true, a wider inquiry into the circumstances surrounding his release is urgently required."
Gwent Police said Williams became unresponsive while under arrest and officers and paramedics administered first aid but he was pronounced dead.
A post-mortem examination was due to be carried out on Williams, a resident of the Sirhowy Arms Hotel, on Saturday, a spokesman for the IPCC said.
Miss Yemm's death is being treated as murder and police are not looking for anyone else. Her family, and officers who attended the incident, are being supported by specialist officers.
Detectives have refused to comment on the specifics of the tragedy but sources confirmed Miss Yemm suffered substantial facial injuries.
Chief Inspector Paul Staniforth of Gwent Police told reporters on Saturday: " The post-mortem for Cerys will start today, but will take some time.
"Speculation about what happened at the scene and the cause of death is unhelpful and very upsetting for the family of the deceased."
Miss Yemm, who worked in sales at Next, is believed to have met Williams through mutual friends.
A friend, described as a "key prosecution witness", told the Sunday Times that Williams had taken a cocktail of drugs on Thursday evening, when he met Miss Yemm.
"He had an ounce of miaow miaow on him and at some stage during the night he injected himself," the man, who did not wish to be named, told the paper.
"He was also taking large quantities of prescription beta blockers given to him to help overcome his drugs habit."
The man said Williams was given the prescription upon his release from prison a couple of weeks ago.
Her family are being supported at their home in nearby Oakdale by specialist officers, who said relatives were too distraught to talk to the press.