For as long as I've been teaching criminal law to police officers (at least 30 years, so far), there's been a common complaint: "It's all well and good for us to learn this cutting-edge stuff, but we have to work for supervisors who don't know this, and they're not going to let us use it."
Unfortunately, these student reactions are often valid. In many departments, by the time someone has been around long enough to make sergeant, lieutenant, or captain, his or her knowledge of criminal law may be sadly out of date.
Much of what I learned in basic academy in the late 1960s is no longer good law. If I were still operating on the basis of 40-year-old understandings, I wouldn't be very effective. The same can hold true for sergeants who are making decisions based on 10-year-old law, or lieutenants with a 20-year-old basis, or captains or chiefs with a 30-year-old basis. The rules and exceptions for criminal investigations change constantly, and those of us who have to apply current law to criminal investigations and prosecutions have no choice but to keep up with what's new.
But how are police supervisors going to do that? They send their subordinate officers to regular update training on nuts-and-bolts subjects such as search and seizure, interrogations, and other fields of specialized knowledge that patrol officers and detectives use on the job every day. Those officers return to duty from their training classes, armed with the latest court rulings.
But sometimes, officers who want to apply current law are supervised by superiors who are still laboring under the restrictions of older rulings that have been overturned by more recent decisions. Both the up-to-date officer and the out-of-date supervisor experience frustration over their information gap. Officers can lose respect for their superiors and become demoralized by the thought that they are supervised by someone who knows less than they do about the current state of the law.
The problem is that once they become supervisors, many people (in all kinds of professions—not just in law enforcement), tend to concentrate their further training on management-related topics, allowing their basic technical knowledge to become stale and neglected. The longer they remain in supervisory roles, the more outdated their core police knowledge becomes, and the wider grows the information gap between them and the updated officers they're trying to supervise. The trained officer makes an arrest and search that are perfectly valid under current law, only to have his or her work rejected and criticized by a supervisor who is applying overruled law from an older era. See the problem?
Obviously, the solution is for supervisors to continue to train in the areas they supervise. In addition to taking leadership courses that focus on personnel and management issues and other subjects that modern law enforcement supervisors have to know, they must also be sure to get regular, ongoing updates on developments in criminal law that apply to their operations.
A patrol or detective supervisor cannot afford to be several years out of date on bread-and-butter policing topics. To be able to correct subordinates when they do make mistakes, and to ensure that lawful investigations are not inappropriately criticized, the supervisor needs to know at least as much as subordinate officers, and must keep up to date as changes occur.
For example, a police officer or deputy sheriff who went through the academy in the 1990s might have been taught about court rulings holding officers subject to civil liability for continuing to interrogate a custodial suspect "outside Miranda," after the suspect had asked for an attorney.
If that officer later promoted to sergeant or lieutenant before 2003, he or she might not have learned that the U.S. Supreme Court ruled that year that the lower court rulings were wrong, and that federal civil liability cannot be based on an officer's failure to comply with Miranda procedures. (Chavez v. Martinez)
Similarly, an officer going through the academy in the late 1990s or early 21st Century would likely have been taught that under the Supreme Court's 1995 ruling in Wilson v. Arkansas, unexcused failure to comply with knock-notice procedure when forcibly entering a residence to serve a search warrant could result in the suppression of the evidence seized in the search, under the Fourth Amendment exclusionary rule.
If that officer was a supervisor by the year 2006 and was no longer keeping current on such matters, he or she might be unaware that the U.S. Supreme Court ruled in Hudson v. Michigan that the exclusionary rule does not apply to evidence seized under a valid warrant, even if the officers failed to comply with knock-notice.
Likewise, officers trained prior to 2006 were routinely taught that in community property states, either spouse could consent to a law enforcement entry and search of the family residence over the other spouse's objection. Those who were supervisors when the U.S. Supreme Court abrogated that rule in Georgia v. Randolph might easily have missed the change.
These are only three of the dozens of examples of the shifting legal landscape. The point is that investigative rules are subject to change with each new term of the Supreme Court, and supervisors cannot effectively supervise without staying on top of the changes.