Police in the US state of Missouri named Darren Wilson as the police officer who shot and killed 18-year-old Michael Brown last Saturday.
According to information released by authorities on Friday, the young black man had been a suspect in a "strong-arm robbery" of nearly $50 (37 euros) worth of cigarillos at a convenience store with a friend before he was shot dead around noon.
According to local media reports, the public has responded critically to the police statement, with the family's lawyers claiming the link with the robbery was a "devious" attempt to smear the teenager.
"There is nothing based on the facts that have been placed before us that can justify the execution-style murder of their child by this police officer as he held his hands up, which is the universal sign of surrender," the lawyers added.
Wilson had not known that Brown had been a suspect in a robbery at the time of the shooting, Ferguson Police Chief Thomas Jackson said. He declined to comment on why the officer had stopped the two teens.
The shooting of the unarmed teenager sparked five days of protests over racial profiling and tensions between the black community and police. The partially violent protests, in which police are said to have deployed tear gas, calmed, according to reports, on Thursday evening when the state Highway Patrol took over security and were more understanding of the protesters' message.
Photographs of riot police prior to Thursday sparked a debate among politicians on the "militarization" of police.
"We need to demilitarize this situation. This kind of response by the police has become the problem instead of the solution," AP news agency reported Senator Claire McCaskill, a Missouri Democrat, as saying.
Republican Senator Rand Paul said there "should be a difference between a police response and a military response" to demonstrations.
sb/rc (AP, dpa)