Pomona 12th Street Sharkees are a street gang in Pomona, California. Pomona 12th Street is the largest Hispanic gang in Pomona. The gang members are Sureños and are associated with the Mexican Mafia or La Eme. The gang uses a shark as a mascot. Pomona 12th Street gang will commonly abbreviate the name to "P12" or "PXII." Members will commonly wear Pittsburgh Pirate baseball hats because it displays a "P" on the front. Additionally, members have been known to wear Detroit Tigers baseball hats because it displays a "D" on the front which stands for "Doce" and translated from Spanish to English means the number 12, they will also claim 909 even though it does stand for the IE.

Pomona 12th Street commonly is involved in narcotic sales and extortion as a means of revenue. Members have been known to be involved in murders, shooting, robberies, assaults, identity theft, and auto theft amongst other crimes.

12th Street claims all of Pomona between Mission Boulevard and Philadelphia Street. The heart of their territory is 12th Street, where their main hangout, Madison Park, is located. The park used to be known as Sharkee Park, hence the name.^[1]

In recent years, members have been documented throughout Los Angeles County and San Bernardino County. Additionally, members have been documented in Colorado, Nevada, Arizona and Washington.

12th Street formed in the 1940s, donning the name 12th Street when street signs debuted in Pomona.^[1]

12th Street's main rivals are Pomona Sur 13 Cyclones gang, Cherrieville, Happy Town 13, Olive Street Gang. Both gangs Cherryville and Olive St broke off from 12th Street, with Cherrieville forming in the 1960s and both Olive, and Sur 13 forming in the 1980s.^[1][2]

12th Street made headlines when member Valentino Mitchell Arenas shot California Highway Patrol Officer Thomas Steiner in front of the Pomona courthouse on April 21, 2004, and was sentenced to life without parole in May 2005 for the murder. The courthouse is in the northern border of 12th Street territory.^[3]