He looked nervous. There were almost 50 pounds of a honey-like explosive syrup, in jars, in his rented car. And so much more. So Ahmed Ressam ran.

Had Ressam stayed calm, a human dragnet as broad as three continents and minute as the immigrant apartments near Brooklyn's Coney Island Avenue might have occurred after a terrorist bombing. And FBI officials would not be wondering how deadly an attack this surprising cell of Algerian terrorists was planning, and whether a string of arrests stopped it.

Federal law enforcement can't answer many of the questions about the scope of the bombing plot--yet. They do say that the investigation into the associates of Algerian national Ressam remains red hot. Ressam has not been talking since he was arrested Dec. 14 at a ferry crossing in Port Angeles, Wash., law enforcement sources said. But Ressam's neighbors and some of his friends are talking. What speaks even louder is the potent mix of explosives allegedly discovered in his car that law enforcement authorities say had the potential to kill hundreds.

In addition to the explosives, another of the most troubling components of the unfolding investigative picture, terrorism experts say, is the role of Lucia Garofalo, 35, a Canadian woman who from Dec. 6 to 19 and perhaps earlier drove Algerian nationals across the border at remote New England crossings.

"Maybe there were other trips and other Ressams. The thing that bothers them about that particular event is he had four circuit boxes with him, four bombs," said Vincent Cannistraro, former head of counterterrorism operations for the CIA. "Four is quite enough to have made a major impact. There may be other people. How many people did Garofalo bring over the border in the past year? You just don't know."

Although New Year's celebrations have passed safely and Clinton administration officials are relieved, federal law enforcement leaders say it is not time to relax--based on threats not directly tied to the year 2000 coming out of the Middle East and elsewhere. "It is clear and should be clear to all Americans that the risk of terrorism will continue," said Attorney General Janet Reno.

Amid the flurry of New Year's activity, some law enforcement officials acknowledged that the FBI and the Immigration and Naturalization Service detained people who might have a connection to the bombing plot on lesser immigration charges.

"An Algerian in this country illegally is at a minimum right now guilty of bad timing," said terrorism expert Brian Jenkins. "The fact that people may be brought in on lesser charges in order to lean on them for information . . . is a well-established law enforcement technique."

The questioning in late December of numerous people across the country with some link to Ressam was designed to send a deterrent message, U.S. officials confirmed. They also said they are not aware of numerous others still awaiting hearings, though one individual was in custody for weeks before he had a hearing.

Leaders of a half-dozen Islamic organizations said they lack proof that the terrorism threat sparked widespread infringements of rights by law enforcement.

There were, however, troublesome exceptions. Hussam Ayloush, head of the Council on American Islamic Relations in Southern California, said he received numerous complaints that FBI agents were knocking on doors of Muslims in the week between Christmas and New Year's. None of them were Algerian or were questioned about specifics that linked them to Ressam.

"In reality I don't think it's an investigation. I think they had a long list of people and they wanted to let those people know, 'We know about you, we are watching over you,' " Ayloush said. "Nobody denied that they were very courteous when they visited people, but some of the timing was amazing. A lot were visited 5:30 in the morning, 6:30 in the morning."

FBI spokesman John Collingwood said there is an "intense investigation" but "that does not mean, and we didn't in this instance, target or question people based on their ethnic or religious backgrounds."

For Americans, the story appears to begin with Ressam. But its origins can be traced to Algeria, a North African country where hackings and throat-slittings of civilians have been common occurrences since 1992 in a civil war pitting Islamic rebels--the GIA, known as the Armed Islamic Group--against a military regime. In addition to killing an estimated 75,000 of its own people, the GIA hijacked an Air France flight in 1994.

In 1998, the GIA split over the civilian slayings. Many of the most radical GIA alumni, including some of those arrested in recent weeks or wanted in the United States or Canada, moved into Pakistan and Afghanistan. There, they received military and explosives training and became bit players in an anti-American drama whose chief playwright is often identified as wealthy Saudi extremist Osama bin Laden.

Terrorism experts said that while federal authorities have linked some of those arrested here to the GIA--which has not targeted the United States before--it is possible their affiliation was looser, that they were working under "contract" for others, or that they may have been inspired by bin Laden.

Some of these Algerian radicals landed in Canada. A series of court filings by prosecutors around the country show how a number of them entered the United States and their alleged connections.

On Dec. 6, Montreal-born Garofalo, dressed in flowing Muslim robes, drove to a remote border crossing in Pittsburg, N.H. She spoke to a border agent via video camera. The agent waived her through without looking at her passenger, a man she described as a Canadian. But her passenger, Mustapha Roubici, was Algerian, not Canadian. He spent two days with Garofalo in the United States.

On Dec. 14 at 6 p.m., at the other end of the country, Customs agent Diana Dean noticed a man at another obscure border crossing--in Port Angeles. When she asked him routine questions, his hands were shaking. Ressam, 32, ran. He was caught. The combustible contents of his trunk were sent to the FBI lab.

The next day, on Dec. 15, Garofalo went to the Pittsburg, N.H., border crossing about 2:35 a.m. with a man authorities believe is Mustafa Yasari, an Algerian. But this time, the border agent asked to see Yasari, and the car's trunk. It was crammed with luggage. They were on a country road, rather than the interstate from Montreal to Boston. They were denied entry and told to go to a manned border crossing for more extensive questioning.

Somehow, Garofalo got Yasari across the border elsewhere and returned with him on Dec. 17 or 18. Her third try, on Dec. 19, with Bouabide Chamchi, was aborted when suspicious border agents stopped her and found a false passport in Chamchi's jacket.

More interesting was Garofalo's cell phone. An unemployed mother of three on welfare with $8 in her checking account, Garofalo nonetheless had a cell phone and car bought for her by an Algerian national named Brahim Mahdi, who in a prosecutor's court filing was described as having ties to an arms dealer for terrorists.

More interesting still was one of Garofalo's old friends--Karim Said Atmani.

Atmani was a document forger for the GIA. In 1997 in Montreal, he had given her $700 for a trip to Germany. He had found and helped pay for a lawyer for her husband, an Algerian stuck in Italy because Canada denied him residence.

Atmani also was a roommate of Ahmed Ressam in Montreal.

Ressam's arrest on explosives charges yielded a piece of paper bearing the name of Abdel Ghani, who was arrested in Brooklyn on Dec. 30. He had traveled to Seattle and back, unable to meet Ressam and follow through on their plans to head east.

Bob Blitzer, former chief of domestic terrorism operations for the FBI and now an executive with Virginia-based Science Applications International Corp., said there have been a few more detentions and that significant issues remain to be addressed about Ressam and others.

"I would be thinking, we have this guy," Blitzer said. "What else is out there?"

Terror Importation

Law enforcement authorities have recently arrested a number of people with links to the Armed Islamic Group who they believe were plotting terrorist actions in the United States.

Armed Islamic Group (GIA)

Muslim underground organization seeking to topple the army-backed government in Algeria. Since 1992, when the Islamic Salvation Front's legitimate bid for electoral power was crushed by the army, GIA is believed to have been responsible for 100,000 deaths in Algeria, including brutal hackings and throat-slittings.

Ahmed Ressam, 32

Arrested: Dec. 14 in Port Angeles, Wash.

Had a reservation to fly out of Seattle on Dec. 15 to Chicago, New York and London.

Lucia Garofalo, 35

Arrested: Dec. 19 in Beecher Falls, Vt.

Tried to drive Algerian nationals across the Canadian border on Dec. 6, 15 and 19. Was arrested trying to take Bouabid Chamchi over the border.

Bouabide Chamchi, 20

Arrested: Dec. 19 in Beecher Falls, Vt.

Algerian national, resident of Montreal since 1997, passenger of Garofalo.

Abdel Ghani

Arrested: Dec. 30 in Brooklyn, N.Y.

Was in Seattle from Dec. 11 through 16, when Ressam was there. Told a federal informant that he and Ressam were going to travel to Chicago together to raise money for an Algerian Islamic cause.

Abdel Hakim Tizegha, 29

Arrested: Dec. 24 in Bellevue, Wash.

Entered British Columbia, Canada, while Ressam and Abdel Majed Dahoumane were mixing explosives in Vancouver, B.C., motel.

SOURCES: U.S. government filings in federal court in Vermont, New York and Seattle,; Washington Post interviews with federal law enforcement officials and terrorism experts; wire service reports