of about 20 protesters burst into Thursday's news conference, taking the microphone from police Chief John Patterson and arguing with some attendees who said they wanted to hear more about the investigation.

One protester held a sign saying  Corrupt cops deserve to die too!!! 

Moments earlier, the mayor said the shooting would be  rigorously investigated. 

Once the protesters quieted down, the chief resumed his presentation, promising his department's full cooperation with the state investigation.

Police have released few details

None of the four officers who were detaining Ruiz wore body cameras, but passersby recorded the confrontation on video, and accused the officers of overreacting.

 I thought,  Holy cow - what could have warranted that?' It looked to me like they had him under control,  David Ortiz-Whittingham, who saw officers swarming and heard the gunshots, said Thursday.  Even now, knowing about the knife, did he have to die for it? Could this have been de-escalated? 

The police chief released few details Thursday, saying a Wisconsin Division of Criminal Investigation probe of the officer-involved shooting must run its course.

Earlier Thursday, Madison's independent police monitor, Aeiramique Glass, said police had not yet shared evidence or the officer's identity with her office, which will review the case and can recommend to the district attorney that charges be filed if warranted. She said the department and city are  obstructing what the community and the public  want.

 Let me do my job,  she said.

Patterson said the police were committed to cooperating with Glass.

The chief urges people not to draw conclusions

Patterson has urged caution in reading too much from the cellphone videos. He said none show the perspective of the officers, and additional video that hasn't been released is being reviewed.

The officer who fired his weapon is an 11-year veteran of the force, the chief said. He and the three other responding officers will be placed on administrative leave pending the investigation by the Wisconsin Division of Criminal Investigation, as required under state law.

Patterson said police were responding to calls that someone was attempting to enter parked vehicles, and the suspect fled on a bike before the officers surrounded him. One deployed a taser, but Patterson said the effort failed to control the man.

In the videos circulating online, the man can be seen standing before he's brought to his knees as the officers struggle to force him into a prone position. Then he falls quickly to the pavement after what sounds like three gunshots, and seems motionless as the officers handcuff him behind his back. Arriving officers then escort one of the officers a short distance away.

Patterson said he did not know the extent of the knife injuries sustained by the officer.

 This situation was clearly dangerous,  Patterson said before adding he was saddened by the loss of life.

A neighborhood now accustomed to police shootings

The shooting happened in the middle of an intersection in the popular Marquette neighborhood, less than 2 miles (3.2 kilometers) from the state Capitol. Bystander videos show numerous cars at the scene, with people watching as it unfolds.

 I saw everything! I saw everything! You did not need to kill him! ... We watched it all!  a woman yells in the video recorded by Ortiz-Whittingham. Three loud shots can be heard among the sirens, followed by screams.

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Residents who dealt with two other police killings expressed frustration Thursday.

In 2015, a white police officer shot and killed Tony Robinson, who was biracial, on the same street. Large protests followed, but the district attorney filed no charges, determining the officer was justified. In 2012, Paul Heenan, a white musician, was fatally shot after he had been drinking and mistakenly entered his neighbor's house. That officer was exonerated as well.

The chief acknowledged that the neighborhood  has experienced a lot of trauma  and urged people to support one another.

 I want transparency. I want accountability,  Patterson said.

Questions about race and technology emerge

Black advocacy groups, protesters and politicians are speaking out against the shooting, which has also focused attention on the Madison Police Department's lack of body-worn cameras. The force of around 500 is among the largest in the Midwest that doesn't use the devices.

Madison said Thursday that she expects a police request for $400,000 to be approved, enabling the cameras to be phased in over the next three years. Others lamented that cameras weren't already being used.

The mayor said her budget, which has not yet been released, will include funding for body-worn cameras. She said the city needs to put together a policy for their use before the budget takes effect in January.

And now it's a talking point in the governor's race

The shooting has quickly infused itself into the race to succeed Evers as governor, with voting already underway in the Aug. 11 primary.

Democratic socialist candidate Francesca Hong called the shooting  state sanctioned violence  and Democrat Milwaukee County Executive David Crowley said the reports are  painfully reminiscent of the tragedies we have witnessed in Kenosha, Minneapolis, and far too many communities. 

Republican U.S. Rep. Tom Tiffany called on his rivals to let the state investigation  establish the facts without politicians rushing to judgment.