Sussex Police has been condemned for using handcuffs to restrain a disabled 11-year-old girl Getty

Sussex Police has been criticised for how it dealt with a disabled 11-year-old girl who was handcuffed, hooded, placed in a cell and held in custody unaccompanied for more than 60 hours. The girl, known only as Child H, was arrested three times for minor offences and detained under the Mental Health Act on separate occasions between 2 February and 2 March 2012.

Child H suffers from a neurological disability similar to autism which can cause challenging behaviour, and occasional risks of harming herself and others. However, at the time she was arrested, the girl had not yet been diagnosed but her mother informed police that she believed her daughter was suffering from an autism spectrum disorder.

The force has now been condemned by the Independent Police Complaints Commission (IPCC) for how it dealt with the girl and offered a series of recommendations in dealing with children or adults who are vulnerable and have a mental illness. Following her arrests, Child H was held overnight in a cell on two occasions and was not given access to an appropriate adult (AA) – either a parent, guardian or social worker – for more than 60 hours while she was in police custody.

The police watchdog also found Sussex Police used handcuffs, leg restraints and spit hoods on Child H, yet did not record any reason for its use of force on a number of occasions. Following an investigation, the IPPC has found that 11 officers and one other member of staff have a case to answer for misconduct, including six custody sergeants for failing to ensure an AA was present and two police constables for placing Child H in handcuffs.

The IPCC also made a series of recommendations on how the force could improve how it deals with vulnerable and disabled people in custody, including additional training on detaining vulnerable people and the role of an AA and ensuring officers are accountable for their use of force.

In a statement released via her solicitor, Irwin Mitchell, the 11-year-old's mother described her daughter's contact with police as "nothing short of a nightmare". She added: "At the time her disability meant that she could behave in very challenging ways, but what she needed was patience, respect and the support of her mother. Instead she was locked up in a police station without me or anyone else who knew her for support. I can't accept that it will ever be appropriate for the police to hood a disabled child, regardless of how they behave."

Sussex Police Temporary Deputy Chief Constable Robin Smith said: "We welcome the IPCC's scrutiny and during its investigation the force has adopted many schemes to support vulnerable people and those with mental illness, learning disabilities and substance misuse issues."

"As a chief officer I have a duty to protect officers and the public when we are called on for help, whether the threat comes from a child or someone who is unwell. This is very often the case and it was on several occasions that the girl's mother called for our help. The application of any type of restraint is considered only when the level of resistance causes concern for the safety of the detained person, the officer and other members of the public."

IPCC Commissioner Jennifer Izekor said: "This was a complex investigation, which found Sussex Police officers failed to respond effectively to the needs of a vulnerable child.

"While it is clear Child H had significant behavioural problems arising from her disability, Sussex Police and, indeed other agencies which were – or should have been - involved, did not appear to have the skills and capacity to respond to her effectively. The situation was exacerbated by the lack of understanding of Child H's complex needs.

"The IPCC understands it is not possible to train each and every frontline officer to recognise and understand the complexities of all emotional or behavioural issues. But it is important that officers responding to young people with mental health, emotional and behavioural difficulties have a basic understanding of their needs and how best to deal them."