The nation is abuzz with praise for law enforcement. After months of careful investigation, involving extensive surveillance and international monitoring of travel and financial records, the authorities disrupt a major Qaeda cell operating domestically, arresting the primary conspirators. The conspirators are indicted and detained, and the nation breathes a sigh of relief.
Until the subway explodes.
The situation described above is not, thankfully, what has happened in the wake of the arrests this month of Najibullah Zazi, his father and several alleged confederates in Colorado and New York. Instead, it describes what happened in England in 2004 when the authorities, in Operation Crevice, arrested several terrorists (five of whom were eventually convicted) but had insufficient evidence to charge several other associates. Those other men went on to bomb the London subway on July 7, 2005.
Taken together, the Zazi and British cases illustrate a daunting challenge facing the criminal justice system in dealing with domestic terrorism attacks: law enforcement must constantly balance its need to develop evidence sufficient to convict the conspirators against the potentially devastating consequences of allowing the conspiracy to ripen into an attack.
To arrest the suspects prematurely is to run the risks of acquittal, of forcing prosecutors to advocate and courts to accept overly broad interpretations of existing criminal statutes, and perhaps of arresting innocent people. To decide to wait, however, continuing surveillance in the hope of developing better proof, is to risk losing the suspects and placing the public in mortal peril.
Police departments, prosecutors and the F.B.I. all face similar challenges in other criminal contexts. Anyone who has been involved at a senior level in serious investigations is aware of the suspected sexual predator or armed bank robber — or even the suspected serial killer — who must be left at large because of the lack of admissible evidence. Sometimes, proof is developed and the perpetrator is caught; sometimes, people get hurt.
As a society, we have weighed the risks to public safety in curtailing police power against the risks to public liberty of allowing too much police power. The balance we have struck is reflected in our constitutional protections. The question posed by terrorism, however, is whether the stakes — possibly tens of thousands of deaths — are sufficiently higher to alter that balance in favor of greater government power.
History shows that our decisions have yielded mixed results. During the mid-1990s, the authorities were able to develop strong evidence against Omar Abdel-Rahman, known as the Blind Sheik, and his fellow conspirators who were plotting to blow up New York City landmarks; they were convicted in 1995. In an earlier case, however, the unwillingness of a confidential informant to develop evidence that could be used in court led the F.B.I. to cut ties with him in 1992; the group on which he had been informing went on to bomb the World Trade Center the following February.
Prosecutors in the Zazi case to date have been unable to charge several other suspected co-conspirators — as many as 24, according to some reports. And while Mr. Zazi has now been accused by authorities of conspiring to make bombs, the other arrestees have been charged only with the relatively minor offense of lying to the authorities. Law enforcement is described in several news reports as “stretched thin” as it conducts surveillance of Mr. Zazi’s associates.
This has an ominous precedent: in the wake of the 2004 arrests, British authorities followed the other associates who had appeared on video surveillance with the conspirators, but eventually lost interest and moved on to other investigations. Those forgotten men proceeded to kill 52 people and wound 700 more.
Time will tell whether the decision to arrest Mr. Zazi and his associates was premature. If the case against them does not develop beyond what has been reported, and if no useable evidence is developed against the 24 other men, the decision to arrest will be second-guessed. That would be grossly unfair. From a public safety perspective, law enforcement officers and prosecutors cannot be faulted for acting when they believe that the public is in imminent peril, even if that means compromising an investigation.
The larger issue raised here is whether there is a viable alternative to the nerve-racking game of chicken that law enforcement must play in terrorism cases. The obvious — though extremely unpopular — alternative is the passage of a preventive detention statute.
Such statutes have been upheld in the context of people with a demonstrated proclivity toward violent conduct, like sexual predators; the concept could be adapted, in a way that withstands constitutional scrutiny, to cover people with a demonstrated proclivity toward terrorism. That approach would give law enforcement additional means to disrupt potential terrorist plots. It has the virtue of honesty, obviating the strained and sometimes disingenuous use of material-witness and false-statement statutes that are now frequently used to arrest and hold suspected terrorists, and would remove the temptation to criminalize conduct that borders on free speech.
Still, preventive detention is hardly a panacea. What should the burden of proof be in using “civil commitment” regarding terrorism? When should that burden be adjusted, if ever? How often would a subject’s status be reviewed? How long may someone be held? There is, moreover, something about detaining someone before he has committed an offense that runs counter to our core constitutional values.
The Zazi case may well end up providing more questions than answers. In the absence of some mechanism allowing for preventive detention, the F.B.I. and police must continue to make hair-trigger judgments in real time about whether and when to arrest and charge suspects. Those are decisions our law enforcement officials routinely make, and make well, in other contexts; in terrorism cases, however, we have to ask if the stakes are too high for the system we have in place.