‘And variety. For me as a barrister, prosecuting in South London; policy work on child victims and witnesses; two postings to the Attorney General’s office; setting up and heading the Organised Crime Division in liaison with the Serious and Organised Crime Agency (remembering how we tracked a yacht as it sailed towards the UK, working out the best moment to intercept it); Chief Crown Prosecutor for Sussex, overseeing the prosecution of Roy Whiting for the abduction and murder of eight-year-old Sarah Payne; then Chief Crown Prosecutor for London and the retrial in the Stephen Lawrence murder case and the London Disorder prosecutions.’

Alison joined the newly formed CPS in 1986 from Lloyd’s of London. ‘I have seen the Service grow up. Everyone now understands our independence. We don’t have to make the case. Rather than only becoming involved at the end of an investigation, we now give early advice to specialist investigators – such as in cases of counter terrorism or organised crime – on how to gather evidence and develop the case.’

Her attachment to criminal law goes back to university days at Leeds. ‘I loved university life (too much) and enjoyed my criminal lectures/tutorials which were led by Professor Hogan, who wrote the book! The Lloyd’s of London experience helped in that it opened my eyes to a wider world of law and also the international side.’

Decision-making is still very much part of the job. ‘As DPP, as a result of undertakings given to Parliament over the years, I make the final decisions in prosecutions arising out of deaths in custody and assisted suicide, and also double jeopardy cases.’ On the day of our interview Alison had already conducted one of her regular Director’s case management panels during which she discusses with a group of her prosecutors the decisions they are minded to make in their cases: ‘This fulfils a double purpose – coaching my lawyers and giving me assurance.’

We touched on recent high-profile cases: ‘We aim to keep waiting time for a decision on a prosecution to a minimum. And we don’t give charging advice in cases of investigations into possible crimes by people who are now deceased. The police may of course have different drivers…’ Referring to a recent case where following a review she changed her original decision not to prosecute the ailing Lord Janner for alleged child abuse, she says: ‘It was a really difficult decision for me personally. But I always have to reflect or I’d become pig-headed.’ Alison is generous towards her predecessors who occasionally comment publicly from lofty positions about her cases: ‘They can be helpful if they offer perspectives which as serving DPP I can’t.’

In her 30 years, Alison picks out three significant advances for the CPS. ‘We are again at the front end of the prosecution process, sitting in police stations, deciding charges in a wide range of offences, nearly 300,000 cases annually. Secondly, taking on more advocacy: now that people see us on our feet in the magistrates’ and crown courts, it’s good for our image and self-esteem – and of course recruitment. And I’m proud to say that we have two QCs in the Service, plus many senior advocates.’ She emphasises, however, that although there is a real career for advocates in the CPS she wants a mixed economy with the Bar. ‘We went through a period of doing all our own magistrates’ court advocacy. The Bar was concerned, not just at the loss of the work but also at the loss of learning opportunities for less senior barristers. We now make more use of the Bar in magistrates’ courts. We also encourage secondments from the Bar for periods between three and 12 months as we did during the London Disorders.’ Her advice to new members of the advocacy panels who work for the CPS: ‘Talk to your local CPS; look up our policies; visit the e learning prosecution college; engage with us.’

But it’s not just about advocacy. ‘We value case working skills. I’m pleased that they continue to be of high quality and that despite 25% cuts in recent years the casework has actually improved.’ Talk about casework leads on to smarter working across the CPS. ‘We have gone digital, working successfully with the judiciary to upload our cases on to the crown court system. Judges can now see when we have uploaded a case and we can also move our case preparation more easily round the country to take account of peaks and troughs.’

The third significant change which Alison identifies ‘has been an increase in transparency in how we conduct ourselves, in explaining why we have made our decisions, in our interactions with the public: it’s important that people are confident in the CPS – victims, witnesses and defendants.’

In that connection the BBC 4 three-part series documenting 18 months in the life of the CPS, The Prosecutors: Real Crime and Punishment, served the CPS well. Alison explains delightedly: ‘1.3 million viewers! A critics’ choice every week. It showed how hard our prosecutors work, and how thoroughly. The viewers saw real people who care and are passionate about their work. It has helped with recruitment.’ Which is good news, because after some tough budgetary years the CPS is looking to recruit more prosecutors for their challenging and sensitive areas of work, including rape and serious sex offences, fraud, counter terrorism and international work. Alison was pleased to tell me that the CPS was at the time of the interview also recruiting a batch of 25 trainee solicitors and pupil barristers and had decided to increase its trainee uptake significantly from 2017, a sign of confidence in the future. ‘We are a national and international service, with offices all around the country and with 30 people abroad.’ Washington DC, Rome and the Caribbean were mentioned…

Alison spends time with all new recruits. ‘My main message to them? We are a fantastic place to work. I emphasise the importance of our values: it’s not just about what we do, it’s how we do it. And I tell them “embrace the opportunities that the CPS gives you”. In the Attorney General’s office, the late Dame Juliet Wheldon QC (who was to become the Treasury Solicitor) advised me to take opportunities when they presented themselves; to think ahead; and not to limit my aspirations. Good advice, which I pass on to others. Internally the CPS is good at recognising and respecting the quality of its people. I’ve never felt I had to prove myself as a woman. And it has been satisfying to develop the people in my immediate teams and see them progress over the years. I can now do this on a wider scale. It’s a priority for the Service: giving people the tools and skills for the job and setting a vision for 2020 around our people and their development, including movement in and out of the Service, in from the Bar and back, in from solicitors firms and back.’

Alison’s experience in the Attorney’s office has helped her ‘to have a good relationship with the Attorney. He superintends me and protects me from any political interference; and he’s a great supporter on budgetary matters. He gives me advice on cases when I ask him but respects the fact that the decision is mine.’

What about her proudest career moments? ‘Hearing the guilty verdicts in the Stephen Lawrence case. Being appointed as the first internal DPP since the setting up of the CPS. I was told that my appointment was good for morale. I received lots of heartening emails. People felt it endorsed their work and professionalism. Being made a Companion of the Bath, an honour which reflected all the work of the volunteer CPS colleagues on the London Disorders when I was CCP for London, working through the night in fast-moving circumstances.’

Looking forward, Alison’s priorities remain ‘the further development of the CPS. Clarity about advocacy, staff development, morale, interchange, casework quality, sexual abuse, violence against woman and girls (where there has been a recent innovative social media campaign – #ConsentIs – with a potential reach of 45 million to highlight awareness at universities). If I don’t get things right as head of the organisation, who puts me straight? The people around me, and indeed the whole organisation, are not afraid to speak up and tell me when I’ve got it wrong!’

Contributor Anthony Inglese CB, former head of legal at the Government Legal Service and a Bencher of Gray’s Inn