Police have arrested a 16-year-old boy on suspicion of two horrific knife murders which took place three months apart in the same town.
The boy, who would have been just 14 or 15 when the first killing took place, was arrested on Tuesday near the scene of the second murder.
The victim of that attack, Nahid Almanea, a student, was stabbed to death on a footpath through a nature reserve in Colchester, Essex, where she was preparing to begin a PhD course at a local university.
A spokesman for Essex Police said the suspect was initially arrested on suspicion of carrying an offensive weapon.
Only later did officers arrest him on suspicion of the double murders.
The teenager is now being questioned at Colchester police station, the spokesman said.
The first victim James Attfield, a father-of-five, was found with 102 knife wounds on a riverside path in Colchester in the early hours in March last year.
Mr Attfield was found mortally injured in the early hours of Saturday March 29 with wounds on his arms, hands, back, neck and head.
Police said was "one of the most brutal" killings they had ever witnessed.
Mr Attfield, 33, was last seen drinking a pint in the River Lodge pub in Middleborough, Essex, the night before his death.
He was said to be a quiet, shy man who steered clear of trouble after suffering brain injuries in a car accident four years ago.
Miss Almanea was murdered as she walked from her student accommodation to the university complex at around 10.40am on June 17 last year.
Paramedics tried to save her following the attack on the Salary Brook Trail in Colchester, a short cut through a nature reserve, but she died at the scene.
She often walked along the path with her brother, who lived with her, but was alone when she was attacked.
Miss Almanea had only moved to Britain six months before she was killed.
She was taking an English language course ahead of commencing a PhD in life sciences.
Essex Police confirmed the teenage suspect was arrested around 11am on Tuesday on the Salary Brook Trail.
He was initially held on suspicion of possessing an offensive weapon but was later re-arrested on suspicion of both murders.
Up to 11 other people have been previously arrested in connection with the murder of Mr Attfield.
Det Chief Supt Steve Worron, of Essex Police, said in March that the force had spent over 100,000 hours on the investigation.
Officers are understood to have spoken to more than 1,000 people, taken 1,300 statements and studied hours of CCTV footage in the investigation.
Mr Attfield's mother Julie Finch, from Essex, shared a link of the news of the teenager's arrest on her Facebook page.
She wrote: "14th months today since Jim was so brutally taken at last let's hope we get justice for our lovely Jim.”