It happened on the A1 near Dunbar.
807 Police Officers Quit Single Force
Since the eight forces merged into one in April 2013, 807 officers have resigned.
The figures, obtained by Heart using Freedom of Information Laws, show the breakdown includes 748 constables, 42 sergeants, 10 inspectors and 7 chief inspectors.
Calum Steele from the Scottish Police Federation says the figure is worrying, He said: "The only reaction I can genuinely express is one of astonishment.
"In excess of 800 officers leaving the service through resignation is an astronomic number, but clearly they do point to some significant issues the service needs to identify and address.
"Of course it's possible that morale was a consideration, but I would be of course more concerned if the historic problem that the police service had in retaining women officers was a significant contributing factor in these numbers.
Mr Steele says the cost of losing so many officers is a major concern: "Losing officers is a very expensive activity. The 807 officer who have left have all had to be replaced; recruitment is expensive, training is expensive.
"It's always been disappointing when anyone has left the service because they felt unable to pursue their career for whatever reasons.
"I would still encourage people to take the view the police service is a fantastic job and for some people does turn out to be a career, but we can't lose sight that over the past eight or nine years in particular, the value in with which public service in general and policing in general has been held, a largely across the United Kingdom, has been diminished.
"Governments have not been able to demonstrate their own confidence and belief in the police service simply because they've undertaken very pernicious attacks on general terms and conditions.
"The sad fact is the police service is no longer an attractive a career options as it once was."
A Police Scotland spokesperson said: "Looking at the last two full years the turnover of police officers for the force sits around 5%, Voluntary resignations only equate to less than 2% of the officer turnover per year.
"Comparatively, this is small and does not at this time give concern. Police Scotland however continues to work with both staff and officers to ensure that we continue to be an employer of choice."
The 26 year old was first targeted in Briarscroft Road.
Euan Johnston was shot in his car last month.
The family of three crash victims took their case for the 59-year-old to be put on trial to the Appeal Court in Edinburgh earlier this year.
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