Ellroy wrote the 1990 novel on which the film was based -- the feature, which was produced by Regency, starred Kevin Spacey, Russell Crowe and Kim Basinger and won two Oscars, one for Kim Basinger's supporting role and another for Hanson and Brian Helgeland's screenplay.
The project is being pitched to cable, broadcast and streaming platforms, though it's not the first time a TV adaptation of the property has been attempted. You can watch a 2003 "L.A. Confidential" pilot starring Kiefer Sutherland in the Spacey role as Detective Jack Vincennes, Josh Hopkins as Officer Bud White and David Conrad as Detectie Ed Exley on the 2008 special edition DVD and Blu-ray release of the movie.
Ellroy recently sold another 1950s Los Angeles-set TV pitch to FX, one based on his 2012 novella "Shakedown," about a fictionalized version of the real Freddy Otash, a vice cop turned private eye/fixer/tabloid employee. Ellroy's writing the project, with Joe Roth and Clark Peterson on board to produce.