Tobin dropped an appeal against his life sentences earlier this month Two fathers are writing to serial killer Peter Tobin demanding to know why he murdered their daughters.
They believe the letters could be their last chance to discover what drove Tobin to kill 15-year-old Vicky Hamilton and Dinah McNicol, 18.
Tobin, 64, of Renfrewshire, is serving life sentences for the murders and that of Polish student Angelika Kluk, 23.
Mr McNicol, 71, of Essex, and Michael Hamilton, 60, of Redding, Falkirk, plan to work together on the letters.
“I really want to aggravate him into him losing his temper yet again, and again, and again – I will keep going just to grind under his skin,” said Mr McNicol.
“I’m going to say things that are wrong to him intentionally in the hope that he will correct me by saying to the police ‘that’s wrong’, which he probably will.”
Tobin was jailed for 30 years in 2008 for the murder of Vicky, who disappeared as she was waiting for a bus in Bathgate, West Lothian, in February 1991.
He was told in December 2009 he would never be freed from prison when he was sentenced for strangling Miss McNichol.
Miss Kluk was murdered in Glasgow four years ago.
Police across the UK continue to investigate whether Tobin was responsible for numerous other unsolved killings of young women.
Mr Hamilton, from Redding, Falkirk, said he had already written one letter to Tobin in London’s high-security Belmarsh prison but never got a reply.
He said: “If I live to be 100, I will never get a visitation to speak to him in jail.
“We want to get some kind of reaction from him, we are hoping it will upset him.
Ian McNicol said he wants to “grind under Tobin’s skin” “We’ve found out what happened to our daughters, but there’s people out there who haven’t found their loved ones.
“I went 18 years without hearing anything and I feel sorry for those still waiting to find out.”
In November 1997, the bodies of Vicky and Dinah were uncovered in the garden of a house once occupied by Tobin in Margate, Kent.
In his first letter to Tobin, written in December last year, Michael tried to appeal to Tobin as a fellow father.
He told Tobin: “She (Vicky) was the love of my life – just like Daniel was yours. Why hurt children, including your own?”
Earlier this month, Tobin dropped an appeal against his sentence.
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