Police in Aurora, Colo., conducted a dragnet at a busy intersection last week, stopping just under 20 cars and detaining about 40 people, many of them in handcuffs. Two hours into the operation, the officers nabbed the bank robber they suspected was among the stopped drivers. They also likely violated citizen rights according to constitutional scholars interviewed by The Colorado Independent.

Attorney David Lane said Wednesday that he has been contacted by several of the people detained Saturday afternoon by Aurora police and that he is looking into whether or not to pursue litigation against the city. He told KHOW later that he thought the city may have been within its rights.

At least one complaint has been filed with the city by one of the people detained.

Department spokesperson Frank Fania said the city has no written policy to cover police behavior in a situation like the one they were confronted with Saturday.

“We could never have imagined that a situation like this would ever come up. Our laws really have not kept up with our technology, which is not an excuse to do just whatever you want, especially if it is not legal. We think it was legal, though,” Fania said.

While Fania would not discuss how police knew the robber was at the intersection, Chief Dan Oates acknowledged on KHOW Wednesday that a tracking device had been secreted by the bank into the money it handed over to the thief.

“I will acknowledge that GPS technology was in play in this event,” Oates said.

Early reports had the chief saying only that the department had information giving them a “virtual certainty” that the robber was among those stopped at the corner.

“It’s hard to say what normal is in a situation like this when you haven’t dealt with a situation like this,” Fania told ABC. “The result of the whole ordeal is that it paid off. We have arrested and charged suspect [Christian Paetsch].”

DU assistant law professor Justin Marceau was especially critical of that remark by Fania.

“That’s not how it works,” Marceau said. “What if the tip had been that the robber lived on my block– no other information? Could they detain and handcuff everyone who lives on my block in the hope of catching one bank robber? No, they couldn’t. The Fourth Amendment is pretty clear.

“I don’t have a problem saying the police violated these people’s Fourth Amendment rights,” Marceau said.

Marceau said that under case law surrounding the Fourth Amendment, any detention of a person beyond a minute or two means the person has been seized.

He said courts have ruled that people can be detained without a warrant for the purpose of public safety, as in the cases of DUI checkpoints which he said police use to keep the highways safe.

Marceau noted that none of the police department comments about Saturday’s situation indicated that the department was motivated by public safety.

“They said they did it to catch a bank robber. If their purpose was to catch a criminal then they need probable cause or reasonable suspicion for each person they detain. If 19 people were detained to catch one, then a one in nineteen chance that a person might be a criminal is not reasonable suspicion.

“Under settled law, this went way beyond what police are allowed to do,” Marceau said.

Fania said that legal scholars and others criticizing the city’s handling of the event do not have all the facts.

“We’ve consulted numerous attorneys, including the city attorney, and we believe we acted legally,” he said.

Chief Oates is also an attorney.

Marceau said people who are detained unreasonably by the police usually decline to pursue litigation. Litigation comes, he said, when someone detained without probable cause is subsequently arrested for possession of drugs or on other charges for which the police had no basis for suspicion.

In this case, though, he said the alleged robber himself may have grounds to claim that he was detained without probable cause and that the evidence in his car was obtained illegally.

In Aurora none of the people involved in the dragnet were injured, but if the robber had come out shooting, for example, and injured or killed innocent people who had been detained, Marceau said they may have had a case based on the fact that they would not have been harmed except that they had been detained illegally.

Fania acknowledged that concern, but asked, “What if we hadn’t stopped everyone at the intersection and he gets away and robs another bank and kills someone?

“We had an overwhelming police presence there and we were prepared to deal with whatever might have happened,” Fania said.

Marceau, who specializes in constitutional law and criminal procedure, said it would have surprised him if the Aurora Police Department had a written policy on how to handle situations like the one it faced Saturday.

“Police departments are reluctant to put policies like that in writing because it would create liability for the city. It is better for the city if an officer violates the Fourth Amendment on his own than if he does so as a result of following a written policy.”

UCLA law professor Eugene Volokh, who writes at the legal blog Volokh Conspiracy, agreed with Marceau that this is a pretty clear cut case of a police department violating the Constitution.

He made many of the exact same arguments Marceau made: that a one-in-nineteen chance that someone has committed a crime does not constitute probable cause and that the detention was not a public safety issue.

Volokh, who was quick to post a critique of the situation on his blog and has since been interviewed by local legal journalist Craig Silverman on KHOW, said the fact the robber was caught without physical injury occurring to an innocent person and without anyone being arrested on unrelated charges does not justify the detention.

“Being handcuffed is no small thing. For most of these people, it was probably the first time they had been cuffed,” he said.

“The Fourth Amendment does not allow you to detain 18 or 20 people in order to catch one criminal. The police are charged with enforcing the Fourth Amendment just as seriously as they are charged with enforcing criminal statutes. We need our police to follow the laws they are supposed to enforce. Enforcement of the law has to be consistent with the Constitution,” Volokh said.

Like Marceau, he said the Aurora police have opened up themselves to being sued, not only by any and all of the innocent people detained, but also by the alleged robber.

“This could lead to evidence being excluded,” he said.

Chief Oates said he had no doubts that the arrest and the evidence would hold up in court.

At the bottom of the whole situation is the Fourth Amendment:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

Discussing how the issue relates to DUI checkpoints, which have been ruled to be constitutional, Lane told The Aurora Sentinel:

And while DUI checkpoints are legal, Lane said courts have ruled that similar checkpoints looking for drugs are not. In those case, Lane said police would likely find drugs, but they can’t stop a mass of innocent drivers.

“Even though you can say with a mathematical degree of certainty that a certain percentage of the cars that drive past any intersection have drugs in them, that doesn’t mean the cops get to stop every car going through an intersection and search it for drugs,” he said.

Lane, a well-known civil rights attorney is the former head of the Colorado ACLU. The ACLU declined to comment for this story.