Breathalysers

[INQUISITOR63]

During a recent ITV oldie " Heartbeat " which reflects life in the Sixties a suspect mentioned his fear of being breathalysed.
I didnt think that this police aid to enforcing a conviction was vogue in those times and hadnt yet come out .
Which springs the question ======= When, exactly did the breathalyser first show its ugly head and when was it first used legally ?

[ummmm]

What do you mean it's 'ugly head'?

[craft1948]

1967