I spent 20 years at the Scottish Bar before becoming the MP for North East Fife.
The life of a lawyer is not so very different from that of an MP.
You often encounter people for the first time when they are in need of help and the police are often the first port of call in any emergency.
During my time as an MP I have found the local police force to be men and women of exemplary character doing their best to help everyone who needs it and often under extremely challenging conditions.
Operational matters and the day-to-day running of the police force are best left in the hands of senior police officers.
However, there are occasions when we should question whether certain powers available to the police can be used in all circumstances and politicians have a role in this.
The chief constable must be operationally independent but he can only exercise that freedom with political agreement and a proper framework.
Scottish Lib Dem leader Willie Rennie MSP has spearheaded the opposition to the use of so-called consensual stop and search of young children.
Children as young as five and six have been asked to consent to be searched by the police when there were no grounds for suspicion that illegal activities were taking place.
In June 2014 the Assistant Chief Constable Wayne Mawson described the practice as “indefensible” and said it would stop.
Earlier this month the BBC reported that since he made those comments, 356 children have been searched by the police.
The BBC also pointed to statistics which showed that while London’s Metropolitan police force (which polices a population higher than that of Scotland) searched only 19 children under nine in the last year, Police Scotland have searched 159.
In response to questions from Willie Rennie, First Minister Nicola Sturgeon announced a review of the use of so-called consensual stop and search and indicated its practice will stop.
Of course the police must have the power to stop people and search for drugs, knives or alcohol where there is a suspicion of illegal behaviour. However, I think most people would agree the use of such tactics on small children is unacceptable.
For anyone to claim this is just an operational matter for the chief constable would duck the issue.
And it is not the first time in recent years police methods have hit the headlines.
I was among a number of MPs and MSPs to question the need for what appeared to be a national move towards routinely-armed policing last year.
I’m used to seeing armed police officers they are a common sight around Westminster and most people will agree the presence of police carrying arms is necessary at high-profile buildings like the Houses of Parliament, particularly during a time of heightened security.
That does not mean, however, it is acceptable for police officers to carry guns while attending routine duties on the streets of Scotland.
Therefore, I was pleased to see the Scottish Police Authority has decided a ban on routinely-armed policing should be maintained.
It is not only policing which is important.
The police are only one part of the framework of our legal system which exists to protect us and our freedoms and to punish the guilty.
But as ever, there is an important balance between freedom and punishment.
Responsibility for proof of guilt rests with the prosecution no one has to prove their innocence.
That proof must be beyond a reasonable doubt the kind of doubt which would make all of us stop before taking a major decision in our own lives.
In Scotland the keystone of our system of justice is corroboration the requirement to have evidence from two sources.
However, this important principle is under siege in Scotland.
Despite the opposition of virtually everyone in the legal profession, the present SNP Government still has it in mind to abolish the rule of corroboration.
I spent nearly four years prosecuting in the High Court, round the country but mainly in Glasgow, in cases of murder, rape, serious assault and child abuse.
From that, I learned the legal system is not infallible.
And as a result, I have no doubt the principle of corroboration must be maintained because it prevents miscarriages of justice.
To the Scottish Government may I coin a phrase it is time tae think again.