Police are seeking to question 55-year-old Ian John McLoughlin, also known as Ian John Baker, in connection with a murder in Hertforshire.
Detectives have released CCTV images of a man wanted in connection with the murder of a pensioner in Hertfordshire.
Police are continuing their search for Ian John McLoughlin after a man, was found murdered in Little Gaddesden yesterday
A murderer who stabbed to death a man from Hertfordshire will have his jail term referred to the Court of Appeal as "unduly lenient".
Ian McLoughlin, 55, was given life with a minimum of 40 years at the Old Bailey last month for the murder of Graham Buck in Little Gaddesden in July.
Mr Justice Sweeney said he was barred from passing a whole-life tariff due to human rights laws.
Hemel Hempstead MP Mike Penning said the Attorney-General had confirmed that the sentence would be referred to appeal judges.
He said: "Whilst it is true that Ian McLoughlin will be a very old man in 40 years' time, that is not the point.
"It is essential that we have the ability to pass a whole-life sentence if it is justified.
"I certainly believe it is justified in this case. McLoughlin has killed three times, on separate occasions.
"It beggars belief that we are unable to pass a whole-life sentence because of his human rights."
Mr Buck was fatally stabbed in the neck when he came to the aid of his convicted paedophile neighbour Francis Cory-Wright, who cried out for help when McLoughlin tied him to a bed and tried to rob him.
Tributes have been paid today to the good samaritan who was murdered in Hertfordshire while apparently coming to the aid of his neighbour.
Graham Buck was stabbed to death in the quiet village of Little Gaddesden at the weekend.
Today police have released CCTV pictures of their chief suspect Ian McLoughlin who is on the run.
It's emerged that the man suspected of murdering a 'Good Samaritan' in a quiet Hertfordshire village was a convicted killer on day release from prison.
Graham Buck from Little Gaddesden was stabbed to death as he apparently tried to help a neighbour who was being attacked.
So far there has been no trace found of the main suspect Ian McLoughlin who police say is extremely dangerous.
Watch Elodie Harper's report...
The family of 66 year old Graham Buck, who was murdered in Little Gaddesden in Hertfordshire on Saturday, has paid tribute to him.
Graham leaves behind wife Karen, two sons and a daughter, two grandchildren, and a wife from a previous marriage.
The family said: “We have no words to express how much Graham will be missed. We were all in such a happy place as a family.
"We haven’t seen him happier than being around his grandchildren, he was so proud. We cannot get over that we have lost him. He’s going to be missed by so many people.
“Graham was a devoted husband, father and grandpa. He was a truly genuine person. He loved us all dearly, as well as our dog, cat and two horses. He appreciated life and got satisfaction from his family being happy and healthy."
His wife Karen added: “I’ve lost my rock. I wouldn’t be able to do half the things I’ve done since being with Graham if it wasn’t for him. He and his family have always been there for me in difficult times. I don’t know what I’ll do without him.”
Mr Buck was a keen golfer and was Captain of the seniors team at his golf club. He also loved cricket and rugby.
His family added: “Graham would have been watching the cricket on Saturday and would have been so pleased with the Ashes result. He was a massive cricket fan.”
Mr Buck leaves behind a wife, two sons, a daughter and two grandchildren.
Police say the murder suspect was on day release from prison.
Police pay tribute to Graham Bucks selfless actions for which he paid the ultimate price. He leaves behind a wife and two sons.
A manhunt is underway after a pensioner was murdered in Hertfordshire. Graham Buck was killed in Little Gaddesden, near Berkhamsted, on Saturday while apparently coming to the aid of his neighbour.
Police have warned that their chief suspect remains at large and is "extremely dangerous". Neighbours have been paying tribute to the victim.
Watch Elodie Harper's report below....