UPDATE, 5 PM: A medical equipment company with a judgment against Conrad Murray has filed suit against MSNBC and other entities to place a lien on any income the doctor receives from the documentary the network plans to broadcast about his experiences in the Michael Jackson case over the past two years. You can view the court filing here.

PREVIOUSLY, 2:44 PM: Michael Jackson’s executors at Ziffren Brittenham have penned a tough letter to MSNBC and parent company Comcast, taking them to task for a plan to air the documentary Michael Jackson And The Doctor: A Fatal Friendship, calling it a way to boost ratings at “a struggling cable network.” The documentary, scheduled for Friday at 10 PM ET, features interviews with Conrad Murray, Jackson’s doctor who on Monday was found guilty of involuntary manslaughter in the popstar’s death. In the letter, obtained by TMZ, the lawyers wanted MSNBC to “exercise proper judgment and refrain from airing this program.”

It also questioned whether any of the producing parties paid for access to Murray, who in the docu said Jackson “begged and pleaded” to get propofol, the drug Murray administered to help Jackson sleep and the one that caused his death. “Thus, MSNBC gives Conrad Murray to shift the blame post-conviction to Michael Jackson, even though a jury considered the evidence and rejected this very argument.”