Significant concerns have been raised about the police investigation of the unsolved murder of Emma Caldwell as a man was finally convicted of her killing 20 years after her death.

Iain Packer, 51, was today found guilty of murder as well as charges against 22 women that included 11 rapes and a string of sexual assaults.

Police Scotland has been told it must "explain itself" following a five-week trial that asked serious questions about its handling over the case and attitudes to violence against sex workers.

In response, Assistant Chief Constable for Major Crime and Public Protection Bex Smith said Police Scotland was "sorry" for the mishandling of the case under the then-Strathclyde Police.

READ MORE: Iain Packer found guilty of the murder of Emma Caldwell

She said: "A significant number of women and girls who showed remarkable courage to speak up at that time also did not get the justice and support they needed and deserved from Strathclyde Police."

Packer was first exposed in April 2015 by a Sunday newspaper, which revealed he had taken Emma to Limehouse Woods, where her body was found, six times but police did not investigate him.

Jim Wilson, who was then editor of the Sunday Mail, said Police Scotland and the Crown Office must now be compelled to explain why Packer was not prosecuted ten years before and why, after his exposure, the reopened inquiry took another nine years.

Mr Wilson accused police of not acting to save "professional embarrassment" in having to admit its errors.

He said: “Iain Packer will finally pay for his crimes but the police and prosecutors who allowed him to remain free for almost 20 years must now also be held to account.

“Police Scotland and the Crown Office had the evidence to convict Packer for almost two decades but did nothing because it was too professionally embarrassing to admit their mistakes and put them right.

“A killer was concealed because the authorities did not want to explain a murder investigation that lasted two and half years, cost £4million, targeted the wrong men and left the prime suspect free to commit more crimes and inflict more grief and misery.”

Police Scotland responded to Packer’s exposure in 2015 by launching an unlawful inquiry to identify The Sunday Mail’s sources before finally, seven weeks later, being ordered to reopen the murder investigation by then Lord Advocate Frank Mulholland.

Mr Wilson added: “The decision to investigate our sources instead of reopening the inquiry into Packer was appalling but only one example of the official concealment, delay and denial that has characterised this scandal.

“Scotland’s justice system failed Emma Caldwell, failed her family and failed all the women attacked and terrorised by Packer in the years he was allowed to remain free.

“His conviction has answered one question but Police Scotland and the Crown Office must now be compelled to answer many more.”

Emma was living in a hostel in Govan when she disappeared in 2005.

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The 27-year-old's body was found just over a month later in woods near Biggar, in South Lanarkshire.

The High Court in Glasgow heard during Packer's trial that a rape allegation was first made against him in 1990 but police were, at the time, "dismissive" of reports made by sex workers.

In 2019, Packer told the BBC journalist Sam Polling he had, in 2007, taken police officers to the woods where Caldwell's body was found while, when giving evidence in court, he admitted taking sex workers to the same spot.

Packer gave multiple statements to police over two years but was never interviewed under caution as a suspect.

In 2015 it came to light that the Lord Advocate had directed Police Scotland to re-investigate Emma's murder and also examine the original inquiry.

The review took seven years: more than 30,000 documents and statements were gathered and reviewed along with in excess of 23,000 productions.

New forensic tests were carried out and new witnesses were identified and interviewed.

Ms Smith added: “Emma Caldwell, her family and many other victims, were let down by policing in 2005.

"For that we are sorry. “It is clear that further investigations should have been carried out into Emma’s murder following the initial enquiry in 2005.

"The lack of investigation until 2015 caused unnecessary distress to her family and all those women who had come forward to report sexual violence."

The senior officer went on to praise the "courage, resilience and determination" shown by Emma's family, in particular her parents, William and Margaret, and the survivors of Packer's "horrific catalogue of offending".

She added: “William is, sadly, no longer here to see this day, but I hope this verdict gives Margaret and all those affected by this case, the justice they deserve.

“This was an extremely challenging re-investigation and without doubt the largest police enquiry of recent times in Scotland.

“Iain Packer was a calculating sexual predator who targeted women over many years. It is hard to comprehend how anyone could carry out such despicable, ruthless acts.

“He took Emma’s life for his own gratification in the most appalling circumstances and cruelly left her body in remote woods hoping to cover his tracks.

“But time is no barrier to justice and I would urge anyone who has been the victim of sexual violence to please come forward and speak to us.

“You will be listened to and you will be supported – no matter when the offences took place."

She added: "We have reflected and learnt from the initial investigation and subsequent re –investigation. "Significant changes have been made in recent years to improve our organisational culture and our response, particularly in respect of investigative structures, victim care and processes to these types of crimes."