Jackson Investigation Mystery Date

11/18/2009 5:43 PM PST BY TMZ STAFF
Big clue in the Michael Jackson investigation -- the LAPD detective leading the probe indicated January 18, 2010 may be a significant date.

MIchael Jackson

Detective Orlando Martinez
asked a Las Vegas judge this AM to keep search warrant documents related to Applied Pharmacy secret until January 18. Law enforcement sources told us previously cops didn't want the warrant made public until the investigation was completed.

As we first reported, the LAPD believes Applied Pharmacy supplied Dr. Conrad Murray with the Propofol that ultimately killed Michael Jackson. They are on the hunt to make sure other pharmacies didn't supply Propofol.