The prime suspect for the murder of Jimmy Mizen, the 16-year-old killed in a bakery at the weekend, is a Turkish teenager. A warrant for his arrest has been issued to all police forces in the country.

Ports are on alert in case he tries to flee. Detectives are trying desperately to trace the youth and were hoping to be able to make an early arrest but a search of several addresses has failed to find him.

They are still trying to piece together what happened in the moments before the attack that left Jimmy lying in his brother Tommy’s arms, bleeding to death from a cut to his neck at the Three Cooks bakery in Lee, southeast London.

The wanted teenager, thought to be 19, is believed to be known to the Mizen family. Jimmy’s mother, Margaret, 55, has said that she felt sorry for the killer’s parents. “I don’t feel anger, I just feel sorry for the parents, because we’ve got lovely memories of Jimmy. They will have such sorrow about their son.”

Her family were alerted that Jimmy had been injured and rushed to the scene a few hundred yards from their home. Speaking at a special Mass yesterday at Jimmy’s school, which he would have been attending for the last time before starting a job with Southwark Council, she said: “I was there as quickly as I could run. It’s a comfort to know my son was there with him.

“I suppose I would have liked to have had him in my arms but I’m comforted by the fact he was in my son’s arms.”

Standing with her husband, Barry, vice-chairman of governors at Jimmy’s school, St Thomas More Catholic Comprehensive School in Eltham, she said that the parents of her son’s killer must be in pain.

“You can imagine, that’s their child, they held that boy in their own arms as a baby. They must be in pain. It’s so painful that their child has been so cruel and so wicked.”

Mrs Mizen, who has six other sons and two daughters, said that she was not filled with anger and that the family’s Roman Catholic faith was a great source of strength. She said: “There is so much anger in the world . . . it was anger that killed my son . . . if I am angry then I am going to be doing exactly the same as this young chap.”

Jimmy was usually at work with his father on a Saturday, helping him in his shoe repair shop, but had been given the day off because it was his 16th birthday on Friday.

He had gone to the shop to buy his first lottery ticket when he was attacked by the youth, who police said was “intent on violence”. He asked Jimmy, a former altar boy, to go outside for a fight but 6ft 4in Jimmy refused so the aggressor smashed in the glass door of the bakery. Jimmy’s throat was cut with a shard of glass.

He was the thirteenth young person to be killed in London this year, compared with a total of 26 last year.

The school’s head teacher Markus Ryan, said that the leavers’ Mass for Year 11 students was dedicated to Jimmy and his family.

He added: “This week would have been the start of the GCSE examination period for Jimmy and his year group. We will be considering very carefully any additional support we may need to offer to Jimmy’s classmates during this already stressful time.”

Detective Chief Inspector Cliff Lyons, who is leading the hunt for the killer, said that his team were going through CCTV footage from the area and had collected “significant forensic material” from the scene of the crime.

He said: “We have also spoken to a number of important witnesses, but believe there are still people out there who saw the incident or events that led up to it because the area would have been busy at that time of day.”

He emphasised that the incident was not being treated as having racial or gang connotations.

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