Partly true.
The gangs are more prevalent in urban. Gang culture non existent in most rural counties. Do not have that culture rural, as I worked in Center twp as a community worker in Indy.....so I saw the difference first hand.
When urban DAs & judges are weak & have catch & release policies that is the biggest difference. That is the solution.....getting stronger DAs and judges.
Now what's not true ....
My daughter runs an ER as head pharmacist that handles 5-6 counties, mostly rural. She says drugs problems are as high here on Per Capita as when she worked the Grady ER in downtown Atlanta. So drugs here too in rural. But DAs/judges work to curb it in rural areas....not catch and release.
On % basis plenty of rural Indiana counties have as high or higher single parent families. So that's not true
https://fred.stlouisfed.org/release/tables?eid=359286&rid=412