Americans, in general, respect the concept of “the law” and those who enforce it. And yet the law and the people tasked with enforcing it do not always reciprocate. In some cases, Americans can jaywalk or even blow marijuana smoke at a police officer, and receive no punishment whatsoever. In other cases, Americans like Mr. Shipman are stopped for violating laws that do not exist. And in still other cases, Americans like Philando Castile, who had been stopped more than 40 times in 13 years for minuscule law violations, are killed because they follow a police officer’s instructions. Frequently, these Americans are black.

African-Americans are disproportionately arrested for jaywalking and other small-scale offenses nationwide. Sacramento police issued more than 200 tickets for jaywalking last year in the neighborhoods of North Sacramento and Del Paso Heights. While just 15 percent of residents of that area are African-American, black residents made up around 50 percent of those ticketed. In Urbana, Ill., the disparity was even more stark: From 2007 to 2011, 91 percent of those ticketed for jaywalking were black, in an area where just 16 percent of residents are African-American.

The Department of Justice found that while African-Americans made up 67 percent of the population of Ferguson, Mo., between 2011 and 2013, they received 95 percent of “manner of walking in roadway” charges and 92 percent of “disturbing the peace” charges. In Minneapolis, the A.C.L.U. discovered that African-Americans were more than eight times more likely to be arrested for low-level offenses, like loitering or driving without proof of insurance, than white residents.

The response to these incidents by other Americans — frequently, but not always, white Americans — is often “well, don’t break the law!” But it’s not about breaking the law, it’s about the enforcement of the law. For millions of Americans, laws can be safely ignored. Jaywalking is sometimes the easiest way to cross a road without sidewalks or where the crosswalk is far away. Speeding, though unsafe, happens when you’re late for work. And sometimes you forget to signal when driving into the grocery store parking lot. But for other Americans — black Americans — any of these simple decisions can result in arrest, fines or even death.

If some people can ignore a law, and others can’t, that law is not being enforced fairly. And if some people can flout law enforcement and survive, and others obey it and die, law enforcement is not doing its job properly. The Constitution guarantees all Americans equal protection under the law. But clearly, it does not guarantee all Americans equal protection from the law.