Red-breasts
.Bow Street runners, who wore a scarlet waistcoat.
“The Bow Street runners ceased out of the land soon after the introduction of the new police. I remember them very well as standing about the door of the office in Bow Street. They had no other uniform than a blue dress-coat, brass buttons … and a bright red cloth waistcoat… The slang name for them was ‘Red-breasts.ʹ”—Dickens: Letters, vol. ii. p. 178.