Jackson also said police were releasing police dispatch records as well as video from a different convenience store where a robbery had taken place on Saturday before the shooting.
He did not say what, if any, link there was between Brown and the robbery. Jackson said he would answer reporters' questions at another briefing later on Friday.
"I cannot discuss the investigation about the attempted apprehension of the suspect in the strong-arm robbery," he said.
"That goes to the county prosecutor's office."
Ferguson police had earlier withheld the name of the officer who shot Brown, citing security concerns. The officer is a six-year veteran on the force with a good record, officials have said. He was placed on paid administrative leave after the shooting.
Police had withheld Wilson's name because of fears that he could be harmed amid the volatile protests that followed Brown's death.