Attribute to someone, especially a wrongdoing or crime. For example, They pinned the murder on the wrong man. This expression uses pin in the sense of “attach.” [First half of 1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
Examples from the Web for pin on
Million drew a breath that made the pin-on tie surge up and down upon the breast of her Jap silk blouse.Miss Million's Maid