Life sentence for Doncaster man who murdered two-year-old step-son

Keigan died in hospital on the 10th of January, days after his second birthday. Credit: South Yorkshire Police

A man from Doncaster has been jailed for life, with a minimum term of 22 years, for the murder of his two-year-old step-son.

Martin Currie, 36, was sentenced at Sheffield Crown Court today for killing Keigan O’Brien in January this year.

The toddler’s mother, Sarah O’Brien, 33, was sentenced to eight years for causing or allowing her son’s death at the hands of Currie.  



Martin Currie, 36 and Sarah O’Brien, 33 Credit: South Yorkshire Police

Keigan died in hospital on the 10th of January, days after his second birthday.

Investigations showed he had been subjected to a significant head injury. This caused a bleed on his brain, which ultimately killed him.

It also became apparent during the trial that Keigan had suffered a number of other injuries in the preceding months, including fractures to his ribs and spine.

It was also revealed during the trial that:

  • From an early stage of O’Brien and Currie's relationship, which began in July 2019, injuries were noticed on Keigan, including black eyes. No medical help was sought by the pair during this time.

  • Analysis of  Currie’s  internet usage on the morning of the 8th January showed that whilst O’Brien was out, Currie had conducted online searches in relation to irregular breathing. Further searches about unconsciousness and gurgling were undertaken when O’Brien returned home.Two hours elapsed before medical aid was summoned for Keigan.

  • Neither defendant was able to give a satisfactory explanation for the little boy’s injuries, which were consistent with his head impacting a hard surface such as a floor or wall, with considerable force.

  • In addition, Keigan’s blood was found on his high chair, on a wall, and on Currie’s clothing.


Having heard all the evidence, the jury decided that Currie inflicted fatal injuries on the defenceless little boy, and O’Brien took no steps to protect her child.  They both then lied about what had happened. Currie is now beginning a life sentence and O’Brien has been sentenced to eight years.

Jill Brookes, CPS

The two people responsible for the pain and suffering Keigan was subjected to are now facing lengthy sentences in prison. Nothing can bring Keigan back, but I hope his loved ones can take closure from today. This investigation has not been easy and you have been in the minds of South Yorkshire Police throughout.

Detective Chief Inspector James Axe, senior investigating officer