Should outside agency lead viral video investigation?

This still frame is taken from a cellphone video of an incident between a Green Bay police officer and a citizen, April 18, 2014.

GREEN BAY - The head of the state's largest police union tells FOX 11 an outside agency should be in charge of the investigation into a viral cell phone video arrest involving a Green Bay police officer.

Jim Palmer is the executive director of the Wisconsin Professional Police Association, which has no affiliation with Green Bay's police union.

Palmer says it’s difficult to tell whether Green Bay Police Officer Derek Wicklund acted appropriately from only watching the video where he is seen taking down a man while trying to arrest him.

“A video captures a particular point and time and a fairly narrow view,” said Palmer.

Police say the incident in the video happened last month as people were coming out of the bars on Washington Street. They say it started when a man took a drink outside of a bar.

Joshua Wenzel is the man seen taken down in the video. He was arrested for disorderly conduct and resisting arrest.

Right now, the Green Bay Police Department is trying to piece together what you don't see in the video. The department is interviewing witnesses and watching dash camera video.

Captain Bill Galvin tells FOX 11 the department’s investigation will likely be complete this week or next week. He says the results of the investigation will then be sent to the Wisconsin Department of Justice for review.

Palmer questions whether the public will trust the Green Bay Police Department's findings.

“If it’s just the Green Bay Police Department or predominately that department doing the review, I think there is going to be a significant segment of the public that's going to not view that as a credible investigation and that doesn't do much to advance the public dialogue,” said Palmer.

A little more than a week ago, Green Bay Police Chief Tom Molitor wrote a letter to the citizens of Green Bay, saying the state department of justice would review the department's internal findings.

“It is my hope that having this outside panel of subject matter experts review the case will demonstrate to the public that we are open and transparent,” wrote Molitor.

“I think that does help considerably, to the extent that the Department of Justice investigators have additional questions or need to interview witnesses independently, they ought to have the ability to do that,” said Palmer.

The state recently passed a law requiring an outside law enforcement agency to review cases of police using deadly force. However, Palmer says it might not be practical to do that with all types of cases where police use force.