Harrison Simpson jailed for life after Cleveland Police fail to arrest him before toddler's murder

Harrison Simpson, 22, has been sentenced to life imprisonment with a minimum term of 28 years and six months for the murder and sexual assault of his girlfriend’s two-year-old daughter, Isabelle Welsh. The sentence was handed down at Teesside Crown Court on 29 July 2026, following a trial that concluded earlier in the week.

Isabelle Welsh died in September 2025 after suffering weeks of abuse, including 21 broken bones, at her home in Thornaby, Teesside. The court heard she sustained an unsurvivable head injury in the 24 hours before her death. Simpson was also convicted of sexually assaulting the toddler around the time the fatal blow was inflicted.

Police failure to execute arrest warrant

Cleveland Police admitted that officers failed to execute an arrest warrant for Simpson issued by Teesside Magistrates’ Court in March 2024. The warrant was issued after Simpson failed to attend court for breaching a non-molestation order, which had been put in place to protect a woman from harassment and threats.

The force said in a statement, as reported by The Sunday Times, that multiple attempts were made to locate and arrest Simpson but these were unsuccessful. Cleveland Police added that a review of the case was conducted immediately after Simpson’s arrest for murder in September 2025.

The review led to changes in how the force manages outstanding warrants. These include improved visibility across the force, a comprehensive data system to track all outstanding warrants, and a governance group led by a superintendent to provide stringent oversight.

Sentencing and court remarks

Ms Justice Norton, sentencing Simpson and Walker, described Isabelle’s murder as the final act in a sustained campaign of violence. She said the death of a young child at the hands of those who should have protected her was particularly distressing for all involved.

Prosecutor Paul Abrahams told the court that the abuse constituted a campaign of deliberate extreme violence. Walker, 26, was cleared of sexual assault but received a life sentence with a minimum term of 22 years for murder and child cruelty.

What happens next

Cleveland Police stated that the review of Simpson’s case has already led to operational changes. The force has not indicated whether further disciplinary action will be taken against officers involved in the failure to execute the warrant. The Independent Office for Police Conduct may conduct its own investigation into the matter.