Since leaving the Metropolitan Police in 2008, Peter Clarke has worked in various sectors: he has been a non-executive director of the Serious Organised Crime Agency, a crisis and risk manager for companies, a fellow of the New York University Center on Law and Security and a trustee of the charity Crimestoppers.
But after less than six months as a board member of the Charity Commission, he says he finds it the most satisfying role so far, mainly because it's a time of great change and challenge - including scrutiny by the National Audit Office and parliamentary committees, and some difficult casework in the pipeline.
He's also full of praise for the staff of the commission and says that, despite cuts and reorganisation, their enthusiasm, intuition and judgement form the bedrock of its work. "Yes, they need direction and leadership, but the goodwill, knowledge and experience are in abundance," he says.
On the downside, he feels he has been stereotyped. "It's frustrating the way some people have commented that my presence on the board is solely to do with the short period in my long police career when I was running counter-terrorism," he says. "I hope what I can bring to the commission is broader than that." He cites his wide experience of managing change in large organisations and working with transport and nuclear regulators.
Another frustration is the suggestion since the appointment of six new members in the summer that the commission board is somehow "a mirror image" politically of what it used to be. "It strikes me as totally inaccurate," he says. " I have been a public servant for 37 years and, because of the nature of my roles, I have been strictly apolitical throughout and will remain so.
"So the suggestion that we have all been brought in as some sort of right-wing coup is silly, frankly. What we actually have is a broad spread of people - if anyone thinks that's unhealthy, it would be interesting to hear why."
Under the new board, Clarke says, there have been changes to make regulation more proactive, including the class inquiry into charities that fail to file their accounts on time.
The commission is also seeking wider general powers to disqualify people from being charity trustees.
Another crucial change since September is that when a statutory inquiry is opened, trustees are required under the commission's statutory powers to provide information. Before then, they were asked in the first instance.
"Some of the cases I have had sight of since I have been here have gone on far too long," he says. "We must find a way of speeding up the process of inquiry. Some of the most difficult cases have gone on so long that the problems have been exacerbated."
He says another area the commission has to drive forward is working in partnership with the security services and other agencies. "By partnership working I don't just mean sharing information, but sitting down together, working out the objectives and the best way of approaching a problem, and then agreeing which agency, with which powers, is best able to achieve a good outcome.
"I'm looking at how we can make it easier for theft and fraud to be reported to the police and acted on, in appropriate circumstances, because that's not always an easy passage. In counter-terrorism, the same applies - who are the partners we are able to best work with? I hope that with my background I can help the commission to broaden and deepen those partnerships - not only in counter-terrorism, but across all law enforcement."
Clarke emphasises that the vast majority of charities, be they Muslim or other, are not involved in any terrorism or support for terrorism, wittingly or unwittingly. "But it would be foolish to ignore the possibility that terrorists are looking to use charities sometimes as a platform for extremist speakers or to radicalise vulnerable young people, or to divert funds, or as a means of moving people into conflict zones."
He declines to give any indication of the number of charities that might be involved in terrorism in some way, saying the answer could be distorted. "From long experience, I know not to play the numbers game," he says. "I used to be asked in my previous roles how many potential terrorists there were in the UK, but the question is meaningless because there are various levels of interest: those who are potentially deeply engaged or those on the periphery of groups. There are those who are sympathetic, and then there are perhaps a number of young people who might be vulnerable."
He defends the commission chair, William Shawcross, against accusations that his remarks on matters such as public service delivery, chief executive pay and diversion of funds to extremist groups in Syria have been unhelpful to the charity sector.
"I think it's right that he should raise these issues for discussion, and I find it slightly strange that he has been criticised for it," says Clarke. "The commission is there to support the sector in its regulatory role, but it's not a question of blind support - it's right that debate should be stimulated by the chair. To suggest he is not supporting the sector because he has opened these issues strikes me as wide of the mark."
2013: Board member, Charity Commission
2008: Independent security consultant
2002: Head, Anti-Terrorist Branch
1997: Head of Royalty and Diplomatic Protection Department
1994: Divisional Commander, Brixton
1977: Joined Metropolitan Police.