(CNN) -- The NFL has a simple answer for critics who claim the league should have been able to get videos of Ray Rice knocking out his future wife and dragging her out of an elevator.
It would have been illegal, Commissioner Roger Goodell wrote in a memo Wednesday to the top officials of the NFL's 32 teams.
"Once a criminal investigation begins, law enforcement authorities do not share investigatory material (such as the videos here) with private parties such as the NFL," he wrote in a note to chief executives and club presidents. "In addition, (New Jersey's) Open Public Records Act excludes material that is generated in the context of an active law enforcement proceeding."
Rice has been suspended indefinitely from the NFL and was cut by the Baltimore Ravens after a video surfaced this week showing him punching Janay Rice, who at the time was his fiancee, in an elevator in Atlantic City on February 15.
Rice was eventually charged with third-degree assault by Atlantic County prosecutors, but as a first-time offender was able to enter into a diversionary program. If he successfully completes the program in one year, the charge will be removed from his record.
Critics have said the NFL should have been able to get the videos and should have banned Rice for life instead of initially giving him a two-game suspension. The ban was increased after the in-elevator video was posted online by TMZ Sports on Monday.
It was the second dramatic video in the case. The first showed the aftermath of the ferocious blow. In it Rice drags his unconscious fiancee off the elevator and talks to a security staffer.
Goodell also said the hotel couldn't legally provide the video to the NFL because of the investigation into the incident.
"We did not ask the Atlantic City casino directly for the video," he wrote. "Again, our understanding of New Jersey law is that the casino is prohibited from turning over material to a third party during a law enforcement proceeding, and that doing so would have subjected individuals to prosecution for interference with a criminal investigation."
Goodell said the Rice legal proceedings are still an "open matter."
TMZ executive producer Harvey Levin told CNN's "The Lead with Jake Tapper" on Tuesday that they paid for the videos.
"I think what happened was the casino closed. And when the casino closed, I think there were a lot of employees who just said, you know what: 'We want to do the right thing.' And ultimately we ended up getting this video because when you look at the video, clearly you see the NFL did not do the right thing," Levin said of the second video. "And I think at a point somebody said that the gain here is worse than the risk, in terms of doing what's right."
The Revel casino closed eight days ago.
The Baltimore Sun petitioned for the release of the elevator video under the Freedom of Information Act, but its request was denied by New Jersey officials.
Copy of letter that commissioner Roger Goodell sent to NFL owners can be read here.