SAN FRANCISCO (NEXSTAR) – A team of investigators calling themselves The Case Breakers say they know the identity of the Zodiac Killer, but law enforcement is refuting their claim. The serial murderer killed five people in Northern California in 1968 and 1969, taunting investigators with with a series of cryptic notes. The Case Breakers, a group of 40-plus members led by retired FBI agents have varied backgrounds in law enforcement, according to their site, and work to solve some of the country’s most notorious cold cases. The Case Breakers have previously attempted to tackle the D.B. Cooper case and the...