The inquiry into Lucy Letby’s crimes has been given statutory footing at the request of her victims’ families.

Letby, 33, was recently sentenced to a whole-life term for murdering seven babies and trying to murder six more.

Here are the key questions about why a statutory inquiry is so important to those affected.

– What is a statutory inquiry?

A public inquiry is set up to investigate a matter of public concern.

According to the House of Commons Library: “Inquiries into matters of public concern can be used to establish facts, to learn lessons so that mistakes are not repeated, to restore public confidence and to determine accountability.”

One of the main advantages of a statutory inquiry over a non-statutory inquiry is that witnesses can be compelled to give evidence under oath.

But a non-statutory public inquiry has more flexibility on procedure rules.

Statutory inquiries are given legal safeguards and “can set limits upon the Government’s discretionary control of an inquiry”, according to the House of Commons Library.

Evidence will be given in public, unless the chair of the inquiry – who is yet to be named – decides otherwise.

– Why has the Government chosen a statutory inquiry over a non-statutory one?

Health Secretary Steve Barclay said that the decision was made after consulting with the families of Letby’s victims.

Many have publicly called for the inquiry to be given statutory footing so will welcome the decision taken by the Government.

– What will the inquiry look into?

The inquiry will look into how Letby managed to carry out her year-long killing spree in the neonatal unit at the Countess of Chester Hospital between 2015 and 2016.

It will also examine wider issues at the hospital, including the handling of concerns and governance.

The inquiry will also look at what actions were taken by regulators and the wider NHS.

The Department of Health and Social Care said the inquiry will “ensure vital lessons are learned and will provide answers to the parents and families impacted”.

Officials said the terms of reference for the inquiry would be published in “due course”.

– Who could give evidence?

Current and former staff of the Countess of Chester Hospital Trust, hospital regulators and wider NHS officials could be among those who are asked to give evidence.

Former hospital bosses could be among those called to give evidence, many of whom have faced significant criticism following Letby’s conviction.

Health commentators could also be called in to speak about wider pressures in the NHS at the time of Letby’s crimes.

There would be legal powers to compel Letby herself to give evidence but it would be a matter for the chair of the inquiry whether they would ask her to do so.

– Who will chair the inquiry?

The Government has said it will look to appoint a judge to chair the inquiry but a chair has not yet been found.

– Are there any negatives about a statutory inquiry?

A statutory inquiry can take years to conclude so it could take longer for the families to get the answers they seek.

For the taxpayer, a statutory inquiry comes with a hefty bill from the public purse and can cost millions of pounds to conduct.

– What about inquiries into other scandals at NHS organisations?

Some scandals have been handled by external reviews, some by non-statutory inquiries and others, such as the reviews into poor care at Mid Staffordshire NHS Foundation Trust and the Infected Blood Inquiry, were given statutory footing.

The Mid Staffordshire review, led by Sir Robert Francis QC, started as a non-statutory inquiry but was given statutory footing later on.