"I will promise the spouses, the family members and the kids, we will do everything to protect your loved ones who wear this uniform," he said.

But at a different point, he said he takes each day as it comes. "I woke up today and there's no signs we need to do anything different than we did last night."

Johnson said he's dedicated to protecting the rights of people to peacefully protest, but said the "unpeaceful" can't be allowed to harm people or damage property. He said police would pull those people out of the crowd and asked the peaceful to be aware of that.

Speaking about the fire at the Michael Brown memorial Tuesday morning, Johnson said he doesn't know how it started and that firefighters are investigating.

"The unpeaceful protesters who were attempting to say this was law enforcement's fault, that law enforcement didn't put it out ... It started out rather small. Someone could have gone in a home and pulled out a cup of water, a pot of water, to put it out," Johnson said. "Instead they stood there for 11 minutes watching it burn until police got there, and ran door to door saying police started this fire."

He said he doesn't believe a law enforcement officer would have started it.