Californian penal code number for homicide. The police in California uses the penal code numbers as shorthand on the radio. Eg. in Oregon the code for homicide is "163.005" - different from California.
"Yeah, and you don't stop, cause it's 1-8-7 on an undercover cop, yeah, and you don't stop, cause it's 1-8-7 on an undercover cop." (Snoop Doggy Dogg on Dr. Dre's Deep Cover (187 on an undercover cop)]
"March 19th 1997 L.A. California, another 1-8-7" -- City Clay ("Tupac and Biggie Tribute")
A.K.A. 187 "The Big Bitch....statutory murder rap" (Fortress (Movie) 1993)
"It's about coming up and staying on top, and screaming 1-8-7 on a motherfucking cop. As long as I'm alive Ima live illegal" -- Sublime, "April 26th, 1992"
"Spades is the sickest illest realest ever heard of, 187 M-16 its murder (" Spades and Elonskee")