First amendment attorney Paul Cambria is representing art professor Steve Kurtz in the following case:

NEW YORK — “A forensic investigation of FBI trash.” On the telephone, Beatriz da Costa says it wryly. Her humor sounds bitter. She’s talking about the detritus of a terror probe at the Buffalo home of her good friends, the Kurtzes.

She’s talking about the pizza boxes, Gatorade jugs, the gloves, the gas mask filters, the biohazard suits: the stuff left by police, FBI, hazmat and health investigators after they descended on the Kurtz home and quarantined the place.

The garbage tells a story of personal tragedy, a death in the Kurtz household, that sparked suspicions (later proved unfounded) of a biohazard in the neighborhood. And it tells a story of the times in which we live, with almost daily warnings about terror, and with law enforcement primed to pounce.

Steve Kurtz, a Buffalo art professor, discovered on the morning of May 11 that his wife of 20 years, Hope Kurtz, had stopped breathing. He called 911. Police and emergency personnel responded, and what they saw in the Kurtz home has triggered a full-blown probe — into the vials and bacterial cultures and strange contraptions and laboratory equipment.

The FBI is investigating. A federal grand jury has been impaneled. Witnesses have been subpoenaed, including da Costa.

Kurtz and his late wife were founders of the Critical Art Ensemble, an internationally renowned collective of “tactical media” protest and performance artists. Steve Kurtz, 48, has focused on the problems of the emergence of biotechnology, such as genetically modified food. He and the art ensemble, which also includes da Costa, have authored several books including “Digital Resistance: Explorations in Tactical Media” and “Electronic Civil Disobedience and Other Unpopular Ideas,” both published by Autonomedia/Semiotext(e).

The day of his wife’s death, Kurtz told the authorities who he is and what he does.

“He explained to them that he uses [the equipment] in connection with his art, and the next thing you know they call the FBI and a full hazmat team is deposited there from Quantico — that’s what they told me,” says Paul Cambria, the lawyer who is representing Kurtz. “And they all showed up in their suits and they’re hosing each other down and closing the street off, and all the news cameras were there and the head of the [Buffalo] FBI is granting interviews. It was a complete circus.”

Cambria, the bicoastal Buffalo and Los Angeles lawyer best known for representing pornographer Larry Flynt, calls the Kurtz episode a “colossal overreaction.”

FBI agents put Kurtz in a hotel, where they continued to question him. Cambria says Kurtz felt like a detainee over the two days he was at the hotel. Paul Moskal, spokesman for the Buffalo office of the FBI, says the bureau put Kurtz in a hotel because his home had been declared off limits. The probe, Moskal says, was a by-the-books affair from the very beginning.

“Post-9/11 protocol is such that first-responders have all been given training about unusual things and unusual situations,” Moskal says.

And obviously, says Lt. Jake Ulewski, spokesman for the Buffalo police, what the cops eyeballed raised some alarms. “He’s making cultures? That’s a little off the wall.”

Erie County health officials declared the Kurtz home a potential health risk and sealed it for two days while a state lab examined the bacterial cultures found inside. Officials won’t divulge what precisely was examined, but it turned out not to be a danger to public health. And the house was reopened for use.

Still, federal authorities think something in that house might have been illegal, Cambria surmises. But Cambria denies there was anything illegal in the house. William Hochul Jr., chief of the anti-terrorism unit for the U.S. attorney’s office in the Western District of New York, would not comment on the investigation.

Kurtz, on Cambria’s advice, isn’t speaking to the press either.

Da Costa, a professor at the University of California at Irvine who has flown to Buffalo to help out, says Kurtz is “depressed” and dealing with the loss of his wife, who died of a heart attack. Today the Buffalo arts community will memorialize her.

Adele Henderson, chair of the art department of the State University of New York at Buffalo, where Kurtz has tenure, is among the people who’ve been questioned by the FBI.

On May 21, she says, the FBI asked her about Kurtz’s art, his writings, his books; why his organization (the art ensemble) is listed as a collective rather than by its individual members; how it is funded.

“They asked me if I’d be surprised if I found out he was found to be involved in bioterrorism,” she says.

Her response? “I am absolutely certain that Steve would not be involved.”

They also asked about “his personal life,” Henderson says, but she would not describe the questions or her responses.

The investigation, she says, will have no bearing on Kurtz’s standing at the university, where he is an associate professor. (Prior to Buffalo, he taught at Carnegie Mellon University.)

“This is a free speech issue, and some people at the university remember a time during the McCarthy period when some university professors were harassed quite badly,” she says.

Nonetheless, considering the kind of art Kurtz practices and the kind of supplies he uses, “I could see how they would think it was really strange.”

For instance: the mobile DNA extracting machine used for testing food products for genetic contamination. Such a machine was in Kurtz’s home. His focus, in recent years, has been on projects that highlight the trouble with genetically modified seeds.

In November 2002, in an installation called “Molecular Invasion,” Kurtz grew genetically modified seeds in small pots beneath growth lamps at the Corcoran Gallery of Art, then engineered them in reverse with herbicide, meaning he killed them.

“We thought it was very important to have Critical Art Ensemble here because we try to have our visiting artist’s program present work that takes our curriculum to the next step,” says Denise Mullen, vice dean of the Corcoran College of Art and Design, whose Hemicycle Gallery hosted Kurtz’s molecular exhibit.

Beyond the cutting edge of art, she says, “we want work that is really bleeding edge.”

In Buffalo, in the aftermath of the bioterror probe that has found no terror, activist artists have scooped up the refuse from the Kurtz front yard and taken it away, perhaps, says da Costa, to create an art installation.