Occasionally asked

Here's the situation: people have heard about a crime in the local news media. The stories identify a suspect, and at least part of the evidence connecting him or her to the crime. Some people can't figure out why the police haven't arrested the suspect. I am occasionally asked about the cause of what seems to be a delay in arresting a suspect when the evidence looks conclusive to the general public. Here are the some of the more common potential causes that come to mind:

• The case needs more work. We haven't quite established probable cause, or we'd like to gather some more evidence to bolster the case first, even though probable cause already exists. Lab results an take a good long while, as can certain kinds of financial records and analysis. Sometimes it is better to tie up these loose end before the arrest is made, even if you've already got enough evidence to reach the probable cause threshold. Probable cause won't convict--that requires proof beyond a reasonable doubt. Obviously, you don't just want to arrest the defendant, you'd like to see him convicted.
• It's a matter of timing. You may want to stage things in a particular order. This can sometimes help things develop. The arrest of one subject may cause an inculpatory reaction by another, for example. Occasionally, suspects are in a rush to get their story in before somebody else, and it may be advantageous to let them jawbone away to their heart's content for a while. People, especially suspects, are sometimes more helpful when nobody is in jail. Sometimes suspects continue to do things that provide more and more evidence--like clumsily try to cover their tracks, arrange alibis, confide in other people who will later become witnesses, and so forth. Waiting and watching can be quite productive in some circumstances.
• The suspect is hospitalized. When you are arrested, the taxpayers become responsible for the cost of your care--even if you are perfectly able to pay, and even if your injury or illness is your own dumb fault. Arrest a drunk driver who injured himself in a traffic crash, and the taxpayers foot the bill. This can be tens of thousands of dollars. Why not wait until later to effect the arrest after he or she has been released?
• The suspect committed a traffic infraction causing an injury crash. If the injury is serious, we may not issue a citation right away, because we want to see how the victim is doing. Because traffic tickets can be easily disposed of with a waiver, special caution is needed. If we were to give the violator a ticket for something like failure to yield the right of way, and he or she simply pled guilty by waiver and paid a fine, it would be impossible to prosecute for misdemeanor motor vehicle homicide later, in the event to the victim's death. Double jeopardy is prohibited by the fifth Amendment to the United States Constitution.

Every case is different, and in protracted investigations, we generally are looking at the pros and cons in deciding when the time is right. This is often done in consultation with the prosecutor. If the defendant is not an escape risk, is unlikely to flee the jurisdiction, and unlikely to commit additional crimes that present a risk to others, then time is on our side and we can make the arrest on our own terms. In other cases,we have to act as quickly as possible once probable cause has been established. Public safety is the primary consideration.