You are still only looking at large population centers - at that scale they will have the largest concentrations of lower income residents (the primary determinant). However, if you go to smaller groupings, like the county level it changes again (unfortunately I only have this data from 2017).

1. ORLEANS PARISH, LOUISIANA
   Homicide rate: 43 homicides per 100,000 people
   Median household income: $36,792
   New Orleans crime index: 6 out of 100

Orleans Parish, while the smallest parish by land area in Louisiana, has the highest homicide rate not only in the state but in the country. Orleans Parish is home to almost 400,000 people and includes New Orleans, the largest city in the state. New Orleans accounts for the majority of the homicides in this county, and in a metro to metro area comparison, it has a higher homicide rate than Chicago. Just 85 percent of Orleans Parish residents have a high school diploma, lower than the national average of 88 percent. 27 percent of county residents live in poverty.
2. COAHOMA COUNTY, MISSISSIPPI
Homicide rate: 37 homicides per 100,000 people
Median household income: $28,851
Clarksdale crime index: 2 out of 100

Cahoma County is one of two counties from Mississippi to make the top 10. Even as a small county with just over 25,000 residents, Cahoma County is no stranger to violent crime. The county seat of Clarksdale had over 150 violent crimes in 2015, and with a population of about 16,000; that means almost 1 violent crime for every 100 residents. 35 percent of residents of Clarksdale live below the poverty line, and 1 in 5 residents are not high school graduates.
3. PHILLIPS COUNTY, ARKANSAS
Homicide rate: 34 homicides per 100,000 people
Median household income: $26,844
Helena-West Helena crime index: 2 out of 100

Phillips County is another rural county to make this list, with a population of just under 22,000. The county seat is Helena-West Helena. Neighborhood Scout gives Helena-West Helena a crime index of just 2 out of 100, thanks in large part to 166 violent crimes in a population of just over 11,000. In addition to having the lowest median household income on this list, just 77.1 percent Helena-West Helena have a high school diploma, also lowest among these cities.
4. ST. LOUIS CITY, MISSOURI (TIE)
Homicide rate: 33 homicides per 100,000 people
Median household income: $35,599
St. Louis crime index: 1 out of 100
The city of St. Louis, which is an independent city and doesn’t fall within any county, has one of the highest rates of murder in the nation. While ranking fourth on this list, St. Louis’ murder rate has actually skyrocketed over the past few years, topping the 50 mark in 2014 and 2015. It is the only city on this list with a crime index of one, the second lowest score among this top 10. Just 84 percent of St. Louis residents have a high school diploma, and over 27 percent live below the poverty line.
4. BALTIMORE CITY, MARYLAND (TIE)
Homicide rate: 33 homicides per 100,000 people
Median household income: $42,241
Baltimore crime index: 2 out of 100
Baltimore is the largest independent city in the country with over 620,000 residents, and like St. Louis, it has a historically high murder rate. After a period from 2007-2014 where total murders were in the 200s, Baltimore has gone over the 300 murder mark each of the last two years and is on pace to approach similar numbers in 2017. Just 82.5 percent of residents have a high school diploma, and almost a quarter live in poverty. The tension between residents and police reached a boiling point in 2015, after the death of Freddie Gray. Peaceful protests turned into a full-blown riot as police officers were pelted with rocks. Over the course of subsequent riots, over 20 police officers were injured, at least 250 arrests were made and nearly 300 businesses were damaged.
6. PETERSBURG CITY, VIRGINIA
Homicide rate: 32 homicides per 100,000 people
Median household income: $31,798
Petersburg crime index: 10 out of 100
Petersburg is an independent town with a population just over 30,000, making it the smallest independent city on the list. Just 77.9 percent of residents have a high school diploma in Petersburg, and 28 percent of residents live in poverty. Petersburg also has a high rate of property crime, and their unemployment rate has stayed above the national average since 2001.
7. MACON COUNTY, ALABAMA (TIE)
Homicide rate: 27 homicides per 100,000 people
Median household income of county seat: $30,738
Tuskegee crime index: 3 out of 100
Macon County is another rural area to make this list with a population just over 21,00 and the first of two Alabama counties in the top 10. In recent years, the unemployment rate has been well above the national average, including a high mark of 18.9 percent unemployment in January of 2010, when the national rate was 10.6. While the county has an 89 percent high school graduation rate, the median household income is just $30,738 in the county - which puts 25.9 percent of residents below the poverty line. In the county seat of Tuskegee, the odds of being a victim of all violent crime are 1 in 97.
7. DISTRICT OF COLUMBIA (TIE)
Homicide rate: 27 homicides per 100,000 people
Median household income: $70,848
District of Columbia crime iIndex: 3 out of 100
The nation’s capital is also a hub for murder, and in the early ‘90s was known as the murder capital of the nation. D.C. has the highest population of any city or county on this list at almost 700,000 people. In May of 2015, Darron Wint made national headlines after he kidnapped the Savopoulos family and their housekeeper in their home. Wint held the family captive for about 18 hours, extorted $40,000, then killed the family before setting fire to the home. Wint is still awaiting trial, scheduled for September 2018.

Washington is easily the most affluent city on this list, with just 18 percent of residents living in poverty and the only city with a median household income above the national average. However, their unemployment rate is higher than the national average and the chances of being a victim of a violent crime are 1 in 79.
9. WASHINGTON COUNTY, MISSISSIPPI (TIE)
Homicide rate: 25 homicides per 100,000 people
Median household income of county seat: $29,144
Greenville crime index: 2 out of 100
Washington County is home to over 50,000 people. Washington County suffers from consistently high unemployment rates, hovering between 8 and 18 percent since 2008. Over one-third of residents live in poverty in the county seat of Greenville and just 78.7 residents have a high school diploma. Greenville in recent decades has seen a rise in gang activity, much of it coming by way of Chicago.
9. DALLAS COUNTY, ALABAMA (TIE)
Homicide rate: 25 homicides per 100,000 people
Median household iIncome: $27,306
Selma crime index: 0 out of 100
Dallas County has a long history of violence, and in recent years, the area has encountered a spike in gang-related violence in some of the county’s poorest communities. The median income of Dallas County is the second lowest on this list. The unemployment rate of Dallas County is among the worst on this list, reaching over 22 percent just after the start of the great recession and rarely falling below 9 percent since. The crime index of zero makes the county seat of Selma the most dangerous city for overall crime on this list.

These rankings show that homicide can affect areas both rural and urban, and LEOs, as well as other first responders around the country, have to face these situations on a daily basis.