This expression means an individual has been caught in the act of committing a crime. Its original meaning is to be caught after having stabbed someone, where the perpetrator still has blood on his or her hands.
“Red-handed” dates back to the Scottish Acts of Parliament of James I in 1432 and is referred to at that time as “red-hand.” “Red-hand” appears in print many times in Scottish legal proceedings from that point on.
Sir George Mackenzie’s essay entitled A Discourse Upon The Laws and Customs of Scotland in Matters Criminal which was published in 1674 states:
“If he be not taken red-hand, the sheriff cannot proceed against him.”
In Sir Walter Scott’s novel Ivanhoe published in 1819, the shift from “red-hand” to “red-handed” was made:
“I did but tie one fellow, who was taken redhanded and in the fact, to the horns of a wild stag.”
You may want to remember this word the next time you get caught with your hand in the cookie jar.
Historically Speaking 