Police identified Johnson in a tweet during the news conference:
Officers Albert Brown and Kevin Brown said when they arrived at Bramble Park in the city's Madisonville neighborhood, a man matching the description of the person who called 9-1-1 walked down a flight of stairs toward them, with a knife in his hand. The knife, the chief said, was 11 inches long and had a blade that was 7 inches long.
The knife was displayed during the news conference:
When the shots were fired, the chief said, Johnson was less than 20 feet from the officers.
Kevin Brown kicked the knife away from Johnson and then administered chest compressions until first responders arrived. Johnson remained in a hospital Friday. Isaac said his condition is "critical but stable." The officers were not injured.
Johnson, who has no criminal record, will be charged with felonious assault and aggravated menacing, Issac said.
Body camera footage was not released Friday, but Hamilton County Prosecutor Joe Deters is expected to release a review on Monday that could include the release of the footage.
Kevin Brown, a 25-year Cincinnati Police Department veteran, and Al Brown, a 24-year veteran, continue on administrative leave pending investigations.
The officer-involved shooting is the first in 2019. The last such shooting occurred in September 2018 when a gunman opened fire at the Fifth Third Center in downtown Cincinnati.
>> Cincinnati officer uses Taser on preteen
In June, Kevin Brown was cleared of accusations he used excessive force when he used a Taser on an 11-year-old girl who was stealing nearly $54 in items -- candy, beef jerky and infant clothing -- from a Kroger in August 2018.
Brown will be awarded back pay for the seven days he spent suspended after the incident, Fraternal Order of Police president Dan Hils said last month.
Hils' announcement followed a finding from an arbitrator that Brown followed CPD guidelines about use of force, which then permitted the use of a Taser on anyone between the ages of 7 and 70, although he had failed to warn the child before stunning her and did not turn on his body camera until after she had been detained.
The police department settled with the child's family for $240,000.