EVIL Alexander Pacteau was willing to prey on any woman who crossed his path, detectives have revealed.

Detective Superintendent Jim Kerr branded the 21-year-old "callous and calculated" and said he had gone out looking for a victim the night he met Karen Buckley in Glasgow.

More than 500 police officers and civilian staff were involved in the missing persons inquiry and murder probe.

Outside the High Court in Glasgow yesterday, Mr Kerr said Pacteau's brutal attack "could have happened to any female that night".

Mr Kerr, who led the inquiry, said Pacteau’s "lies unravelled" through a combination of information from the community, investigative work and forensic techniques.

He said: "From the moment Karen was reported missing, Police Scotland utilised a wide range of specialist officers to locate her.

"That effort combined search teams working closely with detectives, officers within Greater Glasgow Division and neighbouring divisions as the investigation sought to establish the circumstances surrounding her disappearance.

"For Karen to have disappeared like that was so completely out of character and our investigation moved quickly as concerns for her safety escalated.

"Members of the public played a vital role in helping us unlock the circumstances of her disappearance and that led us to Alexander Pacteau.

"His actions left Karen’s family and friends devastated and impacted upon communities in both Scotland and Ireland."

Police also revealed that 1900 hours of CCTV footage were reviewed by officers working on the case.

Mr Kerr added: "I would like to thank those members of the public who assisted our investigation by providing information which was critical in determining that "Alexander Pacteau lied in his initial accounts to us.

"A significant amount of forensic investigation also helped to establish what really happened to Karen.

"The sheer weight of evidence we were able to gather has, I believe, led to today’s guilty plea.

"As a result, Karen’s family have been spared the further distress of a trial.

"Our thoughts remain with them at this difficult time."

Assistant Chief Constable Malcolm Graham, said: "The support for Police Scotland during the investigation into Karen’s disappearance and murder touched everyone involved.

"Messages of support were received from the public throughout and I believe that played a significant part in helping us prove that Alexander Pacteau was responsible for her death and ultimately to a guilty plea.

"Police Scotland is absolutely focused on keeping people safe.

"Our Major Investigation Teams were quickly mobilised to work alongside officers from other Police Scotland divisions and national resources to establish the full circumstances of Karen’s disappearance.

"Alexander Pacteau’s violent actions were unpredictable and extreme.

"Such incidents are rare in our communities; where such incidents do take place we will carry out professional, thorough and rigorous investigations to bring those responsible to justice."