If Kansas City could get its' murder rate down to at least 10 murders per 100,000 people per year, development and investment would happen much faster east of Troost. It affects the perception of the entire city though.
That rate would still be higher than what both New York and Los Angeles have now. Getting the overall crime rate down citywide would be great. However,the murder rate certainly scares people off. A lot of people still won't drive east of Troost, or invest there. That has to change, because east of Troost is a huge geographic area. You could physically fit St. Joseph, Missouri in that acreage of KCMO that exists east of Troost. I think you could also fit the City of San Francisco in that area.
High crime rates are a primary reason many retail businesses won't go there. It's why many grocery stores aren't there. There are no movie theaters in KCMO south of the river that are east of Troost. None. There are no shopping malls there. No Sears, Kohls, Targets, Walmarts, Dicks Sporting Goods, JC Penneys, or Petsmart.
Below on the map the circle indicates a large area without a theater. That area is much larger than San Francisco.
What you have is a very large section of the city that isn't able to function economically. It isn't just lack of places to shop. It's lack of jobs in the neighborhood to employ people to staff the businesses. Those residents have to travel to Independence and Lee's Summit to shop. Think of all the revenue that Kansas City loses.
Kansas City had around 30 murders per 100,000 in 2017. The City of Miami has about the same population as Kansas City, and it recorded 51 homicides last year. In KCMO, there were 135 homicides in 2018.
Miami used to be called the murder capital in the 1980s with almost 300 murders annually.
In 2018, New York City had a homicide rate of 3.31 per 100,000 people.
Houston had a rate of 11.5 per 100,000.
Los Angeles had a rate of 7.1 per 100,000.
San Francisco had a rate of 6.35 per 100,000.
Denver had a rate of 7.9 per 100,000.
Miami had a rate of 11.2 per 100,000.
Seattle's murder rate was 3.4 per 100,000 people.
Chicago had 24.1 homicides per 100,000
Again, Kansas city had 30 per 100,000.
You solve that problem, and a lot of things will take care of themselves.