(CNN) -- When a black man dies at the hands of a white police officer, not often is there video evidence that could end the speculation and show what happened. 

In the case of John Crawford III, there is video evidence -- and Walmart needs to release the tape to the public immediately. 

Crawford was 22 years old when he and his girlfriend went to the Walmart last month in Beavercreek, a suburb of Dayton, Ohio. They planned to pick up the ingredients for s'mores for a family cookout. Crawford had two young children. 

While browsing, he picked up an unpackaged BB gun from one of the store shelves, and continued shopping. A man named Ronald Ritchie saw him and called 911. A black man was "walking around with a gun in the store," and "pointing it at people," Ritchie told them. 

A few minutes later, Crawford was dead -- shot on sight by police. His last words? "It's not real." The gun was a toy, and it was unloaded. 

(Absurdly, if Crawford had been carrying a loaded assault weapon in a threatening manner, it would have been legal under Ohio's open carry laws. This is exactly why gun safety advocates like myself have so long criticized these laws for creating a culture of fear.) 

Was Ritchie more likely to see phantom danger and call the cops because Crawford was a black man? Were those cops more likely to pull the trigger -- by all accounts, without warning Crawford -- because Crawford was black? In other words, is Crawford dead today because he was black in America? 
what did he say?
 A black man was "walking around with a gun in the store," and "pointing it at people," Ritchie told them.