Image copyright Getty Images

Theresa May didn't quote St Francis of Assisi when she spoke for the first time as Prime Minister outside Number 10, but her faith is if anything a stronger motivator than Margaret Thatcher's was for her.

The public service audit - announced over the weekend - is easy to dismiss as a gimmick; yet this is the same politician who, as home secretary, ordered the police to reduce the use of stop and search, which across England and Wales had seen black people seven times more likely to be stopped than white people.

Mrs May recognised that the use of this power had a corrosive effect on confidence in the police, particularly when, according to the Home Office's most recent figures, for 2013-14, only 12% of what are known as "Section 1 stops" lead to an arrest.

Yet the audit - which is not just about race but will also pull together statistics on issues such as the under-achievement of white boys in education, especially those from poorer backgrounds, relative to other groups - raises some important concerns Mrs May's team will need to answer if it is to become a catalyst for change.

Take the case of deaths in or following police custody. Last year, there were 14 deaths, according to the Independent Police Complaints Commission.

Image caption "If you're black, you're three times more likely to be Tasered than anybody else," says Desmond Jaddoo, a community activist in Birmingham

"We believe sometimes when the police come into contact with a black person who is of reasonable size, they say, 'We're going to have to take this one down heavy,' and the facts are, at the end of the day, if you're black, you're three times more likely to be Tasered than anybody else," Desmond Jaddoo, a community activist in Birmingham, told me, adding: "The figures speak for themselves."

The Taser statistics may do, but other figures need more clarity. For example, deaths after contact with police can include being hit by a patrol car on its way to an incident; few would argue that there could be a racial bias in who gets knocked down.

If the audit is going to tell us something of value, it needs to drill down into the figures and ensure different departments, councils and agencies are recording the same thing in the same way.

Figures can be made to look better or worse depending on over how many years you measure them, a tactic often deployed by politicians trying to put the best gloss on a policy.

Image copyright Conservative Party Image caption "Government can act where there is evidence," says Sam Gyimah, a junior minister at the Ministry of Justice

Sam Gyimah, a junior minister at the Ministry of Justice, told BBC Radio 4's The World This Weekend programme the change of policy initiated by Mrs May at the Home Office meant black people were now four times more likely to be stopped than white people.

Yet this improvement could have been achieved by searching more white people rather than fewer black people. So, the audit needs to be qualitative as well as about numbers.

I asked Cdr Mak Chishty, who speaks for police chiefs in England and Wales on issues of race, religion and faith, whether, since crime did not appear to have increased as a result of fewer stop and searches, they had been a damaging waste of effort.

"You can say actually were they necessary in the first place, but the main important thing is our drive, principles, our values", he told me as he prepared for duty at the Notting Hill Carnival in London.

"We're not there to harass the public. We were doing them where we thought there was a risk."

Mr Gyimah said: "Government can act where there is evidence."

Yet, since much of the evidence that will appear in the audit already exists, the test will be whether it is acted upon.

Mr Gyimah is confident it will "drive real change in our public services"

"It will also empower the citizens," he said.

"Everyone in this country will be able to look at these data sets, and you hold public services to account."

Image copyright PA Image caption Black Lives Matter protesters occupied a CPS office in Birmingham to raise awareness of the case of Kingsley Burrell

Kedisha Brown-Burrell has been attempting to do that since 31 March 2011, the day her brother's life support machine was switched off. Kingsley Burrell died after an incident involving West Midlands Police.

"We didn't get any information until the inquest, which was four years later," she told me when we met in Birmingham.

"We started to realise how long Kingsley was under restraint, how long he was sedated, the use of force."

Ms Brown-Burrell is now waiting for a decision by the Crown Prosecution Service over whether or not anyone should be charged in connection with his death. Last week, the family and other campaigners held a demonstration outside the local office of the CPS.

Delays are frustrating, but she told me the worst thing had been the lack of information.

Her anger would have been lessened, she said, if someone in authority had sat down with the family soon after Kingsley's death to explain what was known and what questions still needed to be answered.

"In our culture, we see if anything's going to be prolonged for a long period of time, in our eyes it's being covered up," she said.

Her last remark reveals the challenge Mrs May faces in restoring confidence, particularly within the criminal justice system.

The information in the audit may shine a light on how our public services treat certain groups, but evidence will need to be followed by action.

Shaun Ley presents The World This Weekend during the summer, at 13:00 BST on Sundays, and afterwards available on the BBC Radio 4 website.