Why must St Paul videos be previewed by police before release?

Why aren't the street videos available to us all? Why does the police have to preview the videos before releasing access to the videos? Could "previewing" be code for altering or losing any evidence that might be damaging to the police? Why do we have the ones accused, in this case the police, controlling the evidence?

So while the police are supposedly understaffed and underpaid, somehow they are going to find time to go over the 6.000 hours of street video tape before allowing anyone else to see it.

On Thursday, community groups held a news conference at the state Capitol and said police, not protesters, were the aggressors during the convention. They demanded that more than 6,000 hours of police video be publicly released, saying the footage would show police misconduct and people being wrongly arrested....

Attorneys affiliated with the National Lawyers Guild are representing many of the 818 convention arrestees, and they haven't received copies of the video footage either, said Rachel Bengtson, vice president of the Guild's Minnesota chapter.

St. Paul City Attorney John Choi said all the video would be disclosed to defense attorneys as required by the rules of criminal procedure and court orders.

He also said city officials are working to fulfill video requests made under the Minnesota Government Data Practices Act.

"We have made a conscious decision in the city to be open and forthright with any video that is in our possession," Choi said. "The reality is that someone needs to review the video prior to releasing it, and that is a monumental task requiring lots of staff time."

He said he didn't know when the videos would be ready. The city has received 380 requests for convention-related information, Choi said.
(Pioneer Press)

Why did Choi say, "The reality is that someone needs to review the video prior to releasing it" and why does that have to happen?

Basically there was $69,000 of glass breakage and slashed tires, that allegedly happened from non-police. The accusations are that the police basically tear gassed, pepper sprayed, tazored, and using many violent techniques on people that were not doing any lawbreaking or doing minor things like having too large pole for a banner. Specifically,

Three people detailed their allegations of police brutality. One was Jason Johnson, 33, of Cedar Lake, Ind., who was arrested Sept. 2.

Johnson said he was attending a permitted rally and march that began at Mears Park when he followed a crowd and entered a crosswalk. He said a mounted police officer grabbed him.

"Before I had any time to react to anything at all, I was shot twice by Taser guns," Johnson said. He said it felt like his body was on fire. "I woke up on the ground sometime later, being Tased repeatedly on my legs," Johnson said.

Johnson has pleaded not guilty to obstructing legal process.
(Pioneer Press)

In light the seriousness of the charges against the police, with independent film already providing a basic case, should this same police have control of the video from the street?