Based on an old proverb, "Bad news travels fast," John D. Loudermilk wrote (and Johnny Cash recorded) a song called, "Bad News." The song included the line, "Bad news travels like wildfire, good news travels slow."

That's true in the legal and law enforcement community. If the Supreme Court issues an unfavorable ruling like Missouri v. McNeely (requiring search warrants for forced blood in DUI cases) or Riley v. California (requiring search warrants to examine arrestees' cell phones), the news spreads quickly, and there's a rush to comply with the new restrictions.

But from time to time, we get a really helpful decision that can make our jobs easier, and yet few people seem to learn about it or realize its significance. Here are 10 such decisions from the U.S. Supreme Court (in reverse chronological order). I'm including the year when each ruling was issued, so you can judge for yourself how slowly the good news has traveled (ask yourself how many of these principles you already knew).

Howes v. Fields (2012)
Interrogating officers need not give full Miranda warnings to, or obtain waivers from, a sentenced prisoner who is taken from his cell to an interview room, as long as no additional restraints are imposed and the prisoner is told he need not answer questions and can return to his cell whenever he wants. "Serving a term of imprisonment, without more, is not enough to constitute Miranda custody. Taking a prisoner aside for questioning does not necessarily convert a noncustodial situation into one in which Miranda applies."

Scott v. Harris (2007)
For Fourth Amendment purposes, if the driver of a pursued vehicle is endangering pedestrians or other motorists, officers do not have to engage in lengthy, dangerous, high-speed pursuits until the driver either gives up, runs out of gas, or crashes his vehicle. "Instead, we lay down a more sensible rule: A police officer's attempt [such as with spikes or PIT maneuver] to terminate a dangerous high-speed car chase that threatens the lives of innocent bystanders does not violate the Fourth Amendment, even when it places the fleeing motorist at risk of serious injury or death."

Devenpeck v. Alford (2004)
If your search or seizure is not justifiable on the grounds you subjectively relied on, evidence need not be suppressed, nor civil liability imposed, if the search or seizure is objectively justifiable on other grounds. "Our cases make clear that an arresting officer's state of mind (except for the facts that he knows) is irrelevant to the existence of probable cause. That is to say, his subjective reason for making the arrest [detention, search, seizure, etc.] need not be the criminal offense as to which the known facts provide probable cause. Subjective intent of the officer is simply no basis for invalidating an arrest [etc.]."

Atwater v. Lago Vista (2001)
Regardless of whether an offense is an infraction, a misdemeanor, or a felony, a custodial arrest supported by probable cause does not violate the Fourth Amendment. "If an officer has probable cause to believe that an individual has committed even a very minor criminal offense [seat belt violation] in his presence, he may, without violating the Fourth Amendment, arrest the offender."

Arkansas v. Sullivan (2001)
If you have PC to arrest for a traffic violation or other minor charge, you may make a "pretext arrest" on that charge, just to give you authority to search incident to arrest, hoping to find evidence of more serious charges on which the person can then also be arrested. "A traffic-violation arrest will not be rendered invalid by the fact that it was a mere pretext for a narcotics search."

Richards v. Wisconsin (1997)
If your search warrant affidavit establishes reasonable suspicion that knocking and announcing before entry could endanger officers or permit destruction of evidence or escape, the magistrate can issue a "no-knock" warrant. "In order to justify a no-knock entry, the police must have a reasonable suspicion that knocking and announcing their presence, under the particular circumstances, would be dangerous or futile, or that it would inhibit the effective investigation of the crime by, for example, allowing the destruction of evidence."

Whren v. U.S. (1996)
When you lack reasonable suspicion of criminal activity to justify a vehicle stop, you can rely on observed traffic violations to justify a "pretext stop," and your subjective motivation of furthering a criminal investigation doesn't invalidate the stop. "We have been unwilling to entertain Fourth Amendment challenges based on the actual motivations of individual officers. The Fourth Amendment allows certain actions to be taken in certain circumstances, whatever the officer's subjective intent."

Illinois v. Perkins (1990)
After arrest and before the suspect's Sixth Amendment right to counsel attaches (indictment or first court appearance), you may place the suspect into a recorded cell with an undercover officer posing as his cellmate, and there is no need to Mirandize before that officer begins eliciting incriminating statements. "We hold that an undercover law enforcement officer posing as a fellow inmate need not give Miranda warnings to an incarcerated suspect before asking questions that may elicit incriminating responses."

Michigan v. Long (1983)
As you know, you can frisk a detainee for weapons based on reasonable suspicion that he may be armed and dangerous. But did you also know you may "frisk" a stopped vehicle based on reasonable suspicion that it may contain a weapon, potentially accessible by a dangerous suspect? "The search of the passenger compartment of an automobile, limited to those areas in which a weapon may be placed or hidden, is permissible if the police officer possesses a reasonable belief based on specific facts which, together with rational inferences, reasonably warrant the officer in believing that the suspect is dangerous and may gain immediate control of weapons."

Rawlings v. Kentucky (1980)
A search incident to arrest can lawfully be made even before the suspect is arrested, provided there is PC to arrest before the search begins. "Once police clearly have probable cause to place a defendant under arrest, [and] where the formal arrest follows quickly on the heels of the challenged search, we do not believe it particularly important that the search preceded the arrest, rather than vice versa."

Combining Legal Principles

Sometimes, multiple rulings combine to justify police conduct that might initially appear to be unreasonable. For example, while following the car of a suspect you think is carrying drugs, you see him make an illegal turn, and you make a stop. Believing you had reasonable suspicion of drug activity to make the stop and PC to justify a search, you find narcotics in his pocket, and then arrest him on drug charges. He moves to suppress on Fourth Amendment grounds, and the magistrate finds that you had insufficient facts to justify a narcotics stop and search. How should the court rule?

Under Devenpeck and Whren, the traffic violation objectively justifies the stop, regardless of your subjective motivation. Under Atwater, you had PC to arrest for the illegal turn. Per Sullivan, arrest for the traffic violation justifies the narcotics search. And Rawlings allowed the search to occur prior to arrest. Defendant's motion should be denied.

Moral: Don't overlook the good news.

Devallis Rutledge is a former police officer and veteran prosecutor who currently serves as special counsel to the Los Angeles County district attorney. He is the author of 12 books, including "Investigative Constitutional Law."