Ontario has Toronto, a world-class city, and some boreal forest where people still hunt and trap for a living, and about everything that you could expect in between those different milieus. Contrast Ohio, where forests are either swamps or hills to steep for farming. So practically anything north of a line from Thunder Bay to Sault-Ste. Marie to Sudbury in Ontario is still frontier, and the police are obviously scattered.
The FBI is largely assigned the duty of enforcing the law that prohibits interstate flight to avoid prosecution. Offenders rarely get convicted of interstate flight, but the arrest for interstate flight makes a perpetrator vulnerable to what are usually more severe state laws (murder, kidnapping, rape, robbery, large-scale larceny). Thus the FBI has the reputation of being the law-enforcement least likely to get a conviction on the charges for which it officially makes an arrest. The FBI also has a great crime lab which can seal a conviction or establish non-guilt on trace evidence.
The US Marshals Service has its own story. A hint: it enforces a wide variety of federal laws that the FBI doesn't touch; it protects courts and witnesses; it has been present at Civil Rights rallies and marches to see that nothing goes awry. The FBI might not be able to apprehend a fugitive from Brownsville, Texas who chooses to go to Amarillo or El Paso -- but the US Marshals Service can.
http://www.usmarshals.gov/history/index.html
I prefer a well-trained, well-paid, highly-professional police force, the sort that even with extreme firepower is less likely to make mistakes that kill innocent people even if the killing proves justifiable homicide. Underpaid, ill-trained police are the ones most likely to end up on the informal payrolls of local gangsters. The neighborhood police in China and Cuba are likely to be more politicized to see someone as an "Enemy of the People" to be rounded up and roughed up for what he is instead of for what he does. A thoroughly-honest cop is more likely to see meth paraphernalia scattered among children's toys and show concern about the welfare of the children than anger at the parents. The good cop says that all he does is arrest someone. The bad stuff that happens is the choice of a jury, a judge, and the criminal code.
Police work is one of the most attractive careers for sociopathic types. Why shouldn't it be? It gives great power over often-helpless people. (See also prison guards).