Campaigning all day – and then suddenly – whilst stuffing envelopes with Neil and Monica I remember that I have to do a live radio show. Luckily, I remembered with a half hour to spare. This was for a station in the Midlands and on the revelation through my Parliamentary Question that 24% of citizens who have a DNA profile on the national DNA database (NDNAD) are from ethnic minority communities. This compares with 8% black and ethnic minority members in the general population.

I have come to two conclusions. Firstly – the police are clearly arresting a disproportionate amount of innocent black men. I believe that this is because wherever discretionary powers are used – those powers are used disproportionately. This means that all the work we have all been doing, including the police themselves, to eradicate disproportionality is clearly not working.

I often think whilst a proportion of this – hopefully quite small – is actual racism that the vast majority of it is conditioning. But policing should be about intelligence and evidence – and the challenge has to be to become so professional in carrying out duties that there is no way of telling what an officer is thinking on a personal basis. So – back to the drawing board on how to reduce the conditioning or counter it – so that disproportionality is diminished.

The second conclusion I have come to is that until disproportionalilty in policing is conquered – that this database has unintended consequences. I don’t think, that whilst the new powers to take DNA from those arrested was taken through Parliament that the outcomes had been thought through. It is unquestionable that DNA has moved forward the technological ability to detect crime. So – I have come to accept that a database of those charged and convicted or those cautioned is legitimate. I have also come to believe that checking DNA taken from those arrested and checked against cold cases is legitimate and valuable. Many murders and rapes have been solved that way. However, if DNA that is taken is kept on those who are not charged, cautioned or matched against cold cases – therefore innocent – there can be no reason to keep those DNA records and they should be destroyed.

I think this needs to come back to Parliament for debate. On Thursday in a debate about Forensic Science Services (too long to go into here) I made the same point. Andy Burnham wouldn’t let me come back on the issue of bringing it to the floor of the Commons as he seemed to think that the original debate was enough. I disagree profoundly with him. And for both reasons – the principle of innocent until found guilty which is subverted by the retention of the DNA of the innocent and for the reasons that the database itself is biased towards collection of black and ethnic minority DNA – this issue must come back to the chamber.