HBO is developing a Perry Mason drama series to star Robert Downey Jr. as the unorthodox investigator/defense attorney and be written by True Detective creator Nic Pizzolatto. The project eyes short-run installments in the vein of True Detective, whose seasons have consisted of 8 episodes each. The drama is eyed as an ongoing series, with future seasons’ timing contingent on Downey’s availability and the principals settling on an idea for a new story arc.

The project, which is in the process of securing rights, is believed to stem from the Perry Mason feature reboot Team Downey (Downey Jr. and his wife, Susan) set up at Warner Bros. five years ago. This has been a passion project for Downey Jr. He was attached to star in the movie, which was to be based on an original story by him and David Gambino that was to retain the Noir setting of 1930s Los Angeles from author Erle Stanley Gardner’s source material.

The character of Perry Mason, an unorthodox investigator/defense attorney, was created by Gardner in the early 1930s. Mason has been featured in over 80 novels and short stories, a radio series and six feature films in the 1930s, a comic strip in the early 1950s, an Emmy-winning TV series starring Raymond Burr that ran from 1957 to 1966, the short-lived New Perry Mason TV show from 1973-74, and some 20 made-for-television films that aired during the 1980s and 90s.

The series project, first reported by Variety, falls under Pizzolatto’s overall deal at HBO, which also covers a potential third installment of True Detective, which continues to be in limbo. Pizzolatto and Team Downey executive produce with Joe Horacek.

This would mark Iron Man star Downey’s biggest TV series commitment since his role on Fox’s Ally McBeal.