Man held twice before killing mother

Andrew Cairns, 44, was held by officers from Derbyshire Constabulary on May 26, a week before he killed pregnant Rachael Slack and their 23-month-old son Auden.

The Independent Police Complaints Commission said Cairns, from Ripley, Derbyshire, was initially arrested because of "concerns about his behaviour".

He was released but then detained again the next day after he threatened to kill Miss Slack, 38. He was interviewed before being freed on police bail.

In a statement, the IPCC added: "He was subject to a mental health assessment and allowed to return to his home in Ripley.

"Rachael Slack contacted police the following day, and on the evening of May 27 officers visited Andrew Cairns and arrested him on suspicion of making threats to kill.

"He remained in custody overnight and, following interview and risk assessments conducted on May 28, Mr Cairns was bailed with conditions not to contact Rachael Slack."

Miss Slack and her toddler son were discovered at their Victorian cottage in the picturesque Derbyshire village of Holbrook on Wednesday morning. Both had been stabbed before Cairns turned the knife on himself.

It has since emerged that Miss Slack was three months' pregnant by her new boyfriend.

The IPCC said it was now carrying out its own independent investigation.

The IPCC said one of the conditions placed on Cairns when he was

released a second time was not to contact Ms Slack.

IPCC commissioner Amerdeep Somal said: "Our investigation will look carefully at the extent of the police contact, the decision-making by officers, the involvement of mental health professionals, and the risk assessments carried out.

"We will examine whether Derbyshire police in these circumstances followed relevant policies and procedures for handling domestic violence cases."