Famed defense attorney Alan Dershowitz is getting fed up with the Manhattan DA's office. He understands that charges will likely not be placed against the U.S. Postal Service driver who hit and killed his sister-in-law, lawyer and a retired court-appointed referee Marilyn Dershowitz, and that is okay. But he also knows there is a video in existence that may help his family discover who was driving the other vehicle involved in the accident—and he says the DA's office is stopping him at every pass.

Marilyn Dershowitz had been biking on West 29th Street with her husband Nathan Dershowitz last Saturday when she was struck by the truck The driver continued on, not realizing he had hit someone. "We have been trying so hard to be cooperative with the DA's office in the investigation of my sister-in-law's death," Dershowitz said. "We are getting stonewalled at every turn by William Beach in the DA's office."

And that fact is especially infuriating to Dershowitz as Marilyn Dershowitz's son Adam is in a unique position to help. He works as aeronautics engineer in California and specializes in recreating the moments that lead up to an accident. "All he wants to do is see the surveillance video of the accident to determine if there is anything else to be done to identify the driver of the truck because they still have not identified him," Alan complained to the Post.

The increasingly embattled DA's office has no comment on the matter, but it is worth noting that Dershowitz specifically did not call out the DA himself, Cy Vance, with his beef. "The only person to cooperate was Cy Vance, he called to give his condolences and was very nice," Dershowitz said. The problem apparently is lawyer William Beach. "Every day we call and we get every excuse in the book...He's saying he's too busy. He was too busy Tuesday, Wednesday, yesterday. It's a five minute video!"