The top PR was gunned down in Beverly Hills a year ago (Nov10) as she made her way home after a movie premiere.
Harold Smith, who was described as a "person of interest" in the case, shot himself dead as cops approached him in the lobby of the Harvey Apartments in Los Angeles in December (10).
He had allegedly bragged about murdering Chasen, but her screenwriter brother Larry Cohen had insisted cops had the wrong guy.
Detectives closed the investigation into Chasen's death in July (11).
And now, on the first anniversary of the slaying, bosses at Patrick Spica Productions have announced they're working on a new documentary about Chasen's glitzy life in Hollywood.
The special is expected to debut in France next year (12), according to The Hollywood Reporter.