The defense in the Oklahoma City bombing case faces one of its first major legal tests this week.
At a three-day hearing beginning today, attorneys for bombing suspects Timothy McVeigh and Terry Nichols will argue that key evidence against the defendants be thrown out. They claim that federal investigators mishandled searches and interrogations.
The dispute raises broad constitutional questions about the state of search and seizure laws in the United States. It will also test how far investigators can go in pursuing a suspected criminal.
In dispute are whether search warrants, an incriminating statement from Mr. Nichols, and objects seized from Mr. McVeigh were obtained legally.
Defense attorneys maintain that the procedures were improper and that resulting evidence therefore should be excluded from the coming trial.
Federal prosecutors counter that all searches, seizures, and statements obtained in investigating the April 19, 1995, bombing in Oklahoma City were completed according to the law.
Legal experts say questions about police and FBI conduct are not unusual given the complexity of the investigation.
"I'd be amazed if the question of investigators' conduct didn't come up in a case like this," says Mimi Wesson, a former assistant US attorney and an interim dean at the University of Colorado School of Law. "Every police officer, every government agent, has to be prepared to have their conduct scrutinized."
But she and others say it would also be surprising if the contested evidence were thrown out. Legal experts say the current trend is toward granting law-enforcement officials more latitude in gathering evidence.
"Recent legal decisions support allowing police officers more latitude" in their investigations, Ms. Wesson says. She offers the O.J. Simpson murder trial as an example: Police were considered justified in going to the Simpson estate and poking around after his ex-wife, Nicole Brown Simpson, was killed.
Some observers suggest that the Fourth and Fifth Amendments - which, respectively, protect citizens from unreasonable search and seizure, and guarantee the privilege against self-incrimination - are even being eroded.
"The Supreme Court of the US in the last 20 years has made it easier and easier to establish 'probable cause' for a search. Now, it [probable cause] means something less than it ought to," says law professor Yale Kamisar of the University of Michigan, a specialist in police regulatory issues. "The Supreme Court has been very accommodating in helping law-enforcement people. In cases where there is a lot of subjectivity involved, the general consensus is that the judge tends to side with the police."
Michael Tigar, lead attorney for Nichols, will nonetheless try to convince US District Judge Richard Matsch that federal investigators violated his client's rights. A chief argument is that Nichols's statements to FBI agents during a nine-hour interrogation are invalid because Nichols never signed a Miranda form - which officially spells out the constitutional right against self-incrimination.
But government attorneys insist that Nichols's statements to the FBI qualify as evidence. "Nichols voluntarily made his incriminating statements only after being fully advised of his constitutional rights and treated in a manner consistent with the American system of justice," prosecutors wrote in a brief filed last week. Nichols, they add, refused to sign the Miranda waiver because he objected to the term "interrogation" in the wording. Still, he "orally confirmed that he did understand his rights."
Mr. Tigar also contends that the FBI conducted improper searches of Nichols's home, storage locker, truck, mailbox, and trash cans.
Steven Jones, lead attorney for McVeigh, makes the same assertions regarding searches of his client's car and Arizona mailbox, and seizure of clothing for forensic tests.
McVeigh and Nichols are charged with murder and conspiracy in the bombing of the Alfred P. Murrah Federal Building, which killed 168 people and injured more than 500. The government has yet to decide whether to try them together. If convicted, they could face the death penalty. The trial is expected to begin late this year.