LOS ANGELES -- The boy is 3 and restless in his seat. He plays with a rubber firetruck and bites the wooden bench in front of him until he is scolded. The Los Angeles courtroom is packed. His mother is there. Family friends are there. Suddenly his father is brought in and the room erupts noisily. He watches as his father raises his clasped hands, shackled at the wrists with handcuffs, in a show of confidence, a prediction of victory ...

The boy is grown, a man of 36, a husband and father himself. He stands at his ailing father's bedside in L.A. County General Hospital. A court magistrate arraigns the father to face extradition charges. The father can barely respond. The son tries to slip his father a rosary but someone takes it away.

"If you're accused of being a Nazi, let me tell you, it's worse than being a leper," says Radoslav Artukovic. "Nobody wants to deal with you."

Artukovic is 44 now; his father died four years ago. When the son greets you at the door of his home, you recognize him because you have seen a photograph of his father in a book, saluting Nazi officers. Same dark hair, dark features, broad face.

In 1984, Andrija Artukovic (pronounced ar-TUK-ovich) was extradited from the United States to Yugoslavia to stand trial on charges that he ordered the deaths of thousands of people while minister of interior in World War II Croatia. He was quickly convicted and sentenced to death, but died of natural causes in prison. He'd been called the Himmler of the Balkans. The Justice Department's Office of Special Investigations (OSI), whose major task is to hunt Nazis and Nazi collaborators in the United States, believes he was without question a war criminal, a desk murderer.

But Radoslav Artukovic, his son, sees him as a Croatian nationalist, a revolutionary, a member of a group that made a Faustian pact with Nazi Germany in order to rule its native country. A good man caught in a bad time.

"He's half right," says Aaron Breitbart, a researcher at the Simon Wiesenthal Center here. "It was a bad time."

It was an indisputably bad time: From 1941 to 1945, the Nazi-installed insurgents, who called themselves Ustashi, ran Croatia and engaged in what most historians describe as a campaign of genocide. They killed mostly Serbs but also Jews, Communists, Gypsies and defiant Croats. And they did it with such gusto -- slitting throats, gunning people down, cracking skulls -- that even the German Nazi officials dispatched to check on them reportedly were repulsed. The late Serbian author Lazo Kostich quotes Hermann Neubacher, Nazi envoy to the Balkans, as calling the Ustashi campaign against the Serbs "among the most brutal mass murder undertakings in the entire history of the world."

The Serbs and their allies fought the Ustashi with equal vengeance. When World War II was over and Croatia became part of a reestablished Yugoslavia, the casualties began to be tabulated. Estimates of the number that died at the hands of the Ustashi range from a conservative figure of 250,000 to the more widely used range of 500,000 to 600,000. The violence is part of a long history of ethnic enmity provoked by, among other things, religious differences. War rages again today as Catholic Croats, Orthodox Christian Serbs and Muslims all compete for areas of the Balkans.

When World War II ended, Artukovic was briefly detained by the British before making his way to Switzerland, then Ireland. He traveled under a false name, his son says, to evade the Communists. Andrija Artukovic entered the United States in 1948 also under an assumed name, his son says. His identity was discovered a year later when he used his real name to apply for a visa renewal, and since the early '50s the U.S. government tried to deport him. But it would be more than 30 years before he was officially extradited.

Since that day at his father's bedside arraignment in 1984, Radoslav Artukovic has been waging his own war of sorts, disputing that his father ordered massacres and was responsible for the Ustashi's concentration camps, arguing that he was the subject of a political vendetta by the Communists still running Yugoslavia in the '80s.

But he lobs most of his ammunition at the Office of Special Investigations and has prompted the Justice Department's internal watchdog, the Office of Professional Responsibility (OPR), to investigate whether his father's case was mishandled. Specifically, Radoslav Artukovic claims that OSI officials solicited the Yugoslavs' request for extradition and then lied about it during the hearing. He also charges that the OSI knew there was false evidence in the extradition package and did nothing about it.

Justice Department officials deny all charges -- and stress that it's routine for OPR to investigate any complaint that comes its way. But the complaint comes at a less than auspicious time for OSI's Nazi hunters. It surfaces just when the OSI is under internal scrutiny for possibly bungling a much more publicized case -- that of John Demjanjuk,

the man accused of being Ivan the Terrible.

The problems of the Demjanjuk case -- which Artukovic has followed and studied intensely -- are something of a vindication for him. "I'm starting to smell maybe we've got a really big scandal," he says. But Artukovic is not like Demjanjuk -- this is not a case of mistaken identity. Everyone agrees that this was Andrija Artukovic, a top official in a brutal regime.

Assume No One Believes You

This case is Radoslav Artukovic's passion.

"It's consumed his life," says Lucy Artukovic, the wife of a cousin, with only awe and respect in her voice. "Just look at his house."

There you will find thousands upon thousands of pages of documents culled from archives from Washington, D.C., to Zagreb, Croatia.

They sit on shelves and in file cabinets on one wall of a room that's been converted into an office. Overflow files are wedged into closets and stacked on the dining room table. Requests he made under the Freedom of Information Act have netted him about 100 State Department cables detailing conversations between Justice Department officials and Yugoslav government officials about a possible extradition of his father. In the office are books on World War II -- some dismissed by him as incorrect -- a computer, a fax machine, a leased copier and a crucifix high on a wall overlooking this scene.

He segues from his job as a trader on the Pacific Stock Exchange to investigator and historian, to coach of his 15-year-old son's soccer team.

In fact, he's so accustomed to the trader's frenzied pace and so steeped in the details of his father's cause that he routinely talks on the phone about his father's history at the same time that he issues buy and sell orders.

As he got embroiled in the case, an older trader whom he respected warned him to make a decision: Take care of his father or do his job. "I said, 'I don't have a choice. I've got to do both.' " And after his father died in 1988, even his mother said she would understand if he dropped the crusade. He said he would persevere.

It's not all pure filial devotion. Part of it is the intrigue of the investigation -- he was an investigator briefly during his service in the Army.

"I don't mean to denigrate the seriousness of this," he says carefully as he drives along a freeway en route to pick up his son from a local mall, "but this part with the Justice Department has been fun."

He divides his life between an utterly normal suburban existence and grim forays into the brutal saga of Nazi-allied Croatia. At the modestly comfortable home he shares with his wife and two teenage children in the Orange County town of Seal Beach, he talks into the night about the details of a life his father rarely described when he was bringing up his children in another Seal Beach home.

"If they're interested or ask questions, we'll answer them," he says of his children, Nicholas, 15, and Erika, 13. "But if something's on TV {related to the case}, I don't make them sit down and watch. No. If you're interested, fine. If you're not, you take it at your own speed."

By his own admission, the major part of caring for the children has fallen to his wife. "This is something that's always been a focus of his life, and I knew that from Day One," says his wife, Donna, 48, who serves on a school board in Orange County. "I didn't want to be the focus of someone's life. I knew that I would be with someone who was independent and busy."

His four sisters have helped when they could, but "they have their own families," he says. His father's brother, John, has not been involved in the case. His Austrian-born mother, who essentially supported the Artukovic family when the publicity made her sometime-bookkeeper husband unemployable, still works today in a hospital business office. No one else in the family wanted to be interviewed, according to Radoslav Artukovic.

If the worst thing in the world is being accused of being a Nazi collaborator, then perhaps the most complicated thing in the world is being the child of the accused.

Radoslav Artukovic grew up with controversy and court battles swirling around his father. "It was just part of being an Artukovic," he says matter-of-factly.

He came of age in a supportive Croatian community that told him his father was being harassed for political reasons. "My parents would always say a prayer at the end of the day," he recalls of his devout Catholic parents. " 'Dear Lord, please pray for those people who consider themselves our enemies ...' Something like that." When he was 11, in 1959, the nun who was principal of his school came into his classroom to announce that a U.S. court had denied the extradition request. The class erupted in applause and Rad Artukovic cried with joy.

After that, the family didn't talk much about it.

"I get the impression that it was not a subject that was discussed," says Henry L. deZeng, the self-styled private historian that Radoslav Artukovic hired years ago to research his father's case. "I've even probed -- 'What did your dad say about this? What did your dad say about that?' I think his father just kept it outside the door."

He told his son it was a terrible time. " 'Be glad you didn't have to live through it,' " Radoslav Artukovic remembers his father saying about wartime Croatia.

But by the mid-'80s, when Yugoslavia refiled for extradition, the son had assumed the mantle of his father's defense. Since then, he has raised a six-figure sum of money and spent as much of his own on the cause.

But how do you sell the world on the idea that your father, a top official of a Nazi-allied government, was not a war criminal?

Start by assuming no one believes you. Then get over any hurt feelings that everyone thinks your father is a war criminal. "I cut that off a long time ago," he says.

His personality holds him in good stead -- he's likable and informal if also obsessive and persistent. He prides himself on being able to convince anyone of his integrity if not his father's. (Though he was once politely thrown out of a congressional office by an aide who told him his boss wanted nothing to do with him.)

Friends have been sympathetic and supportive. "The day his father was arrested we had, like, 35 messages on our answering machine. We came back, sat there and listened to them and cried," remembers Donna Artukovic.

"When we were going to the extradition hearings we were verbally abused for a while by the Jewish Defense League," Radoslav Artukovic recalls. "But I talked to these guys every day and, you know, at the end of the proceedings Irv Rubin {head of the JDL} shook my hand. He said that he respected me and that he hopes that his son grows up to be like me. He saw that I'm not full of any hatred."

He's acutely aware that some will cast him as a Holocaust revisionist, a view he denounces. "Before I go out speaking, I read a chapter from a book on the Holocaust to remind myself to keep everything in perspective, to remind myself of what did happen," he says, "even though I'm going to talk about what didn't happen."

And when he preaches to the converted, the Croatians who share his sense of outrage at the way his father was treated, he chastises them for defensively downsizing the number of victims of the Ustashi.

"Sometimes, Croatians say, 'Only so many thousand died... .' I say, 'What do you mean, "only so many thousand"? I don't want to hear that ... that's horrible.' But you know why they say that? They're so sick and tired of being hit with that big figure. And no one ever asks what happened in Serbia."

He haunts lectures of anyone who speaks on this subject. He was in the front row when Yugoslav author Milan Bulajic lectured in southern California on, among other things, the crimes of Andrija Artukovic. He appears at an annual international conference on Holocaust law. "I'm kind of the black sheep, but I think they're getting used to me," he says, laughing. "It's kind of like watching the Academy Awards every year. They pat each other on the back. And then there's this little drip from California who walks in and I ask my one little pathetic question." It's usually on the order of why does the OSI solicit extraditions from other countries.

He doesn't want anyone to think he's trying to shut down the OSI. Though it is OSI that brings out his most strident reactions; he likens

its handling of his father's case to "witch hunting."

But usually he's rather disarming. "You could have 15 courts say we're not going to extradite him and the Wiesenthal Center would still believe what they believe," he says. "Well, that's what makes it a wonderful country."

The Wiesenthal Center's Breitbart agrees that he's a perfectly pleasant man. "Speaking to Radoslav Artukovic, one would have no idea that he was the son of a mass murderer," he says.

Whose Version of the Facts?

What you realize after spending many hours with Artukovic is how difficult it is to establish fact in history -- even history as dissected as World War II.

Even Radoslav Artukovic says he had his moments of doubt about his father. When he first read the government's charges, he was shaken. "It's pretty compelling when you just read their side," he says with a chuckle. So he engaged deZeng, a former accountant whose avocation was Balkan history. "He said, 'The only reason I'm talking to you is because I've been through a lot of these German records,' " Artukovic recalls. "He said if he had felt Dad was involved with the secret police he wouldn't have helped me. That made me feel good, because I had it from someone who wasn't a Croatian, who didn't have an ax to grind."

In the numerous accusations against Artukovic leveled in the extradition request, there's barely a charge that Radoslav Artukovic doesn't condemn -- this person was lying to get out of a Yugoslav prison, that person could never have been where he said he was, and so on.

And over the years, he has bombarded the Justice Department with inquiries, complaints and his own 135-page thesis on this matter, "Anatomy of a Fraud."

Though the extradition complaint contains numerous accounts, the magistrate who heard the case singled out the 1984 affidavits of two people who said they had heard or seen Artukovic ordering deaths.

One man, Franjo Truhar, a Croat police official in the 1940s, said Artukovic essentially ordered the death of an outspoken local politician. The other, Bajro Avdic, who identified himself as a member of an elite police motor escort for the Ustashi, accused Artukovic of personally ordering several massacres. In one case, Avdic said, Artukovic watched as a tank driver plowed into a shed filled with captured partisans.

The problem is this: In the 1950s, both men told different stories. Truhar said in his first affidavit that he knew nothing about the politician's death. Avdic's reports vary in description and time of events. And Artukovic and his researcher have unearthed documents that cast doubt on Avdic's statement that he was part of the motor escort.

Artukovic claims that not only is Avdic's information false but that OSI officials knew about all the variations in the affidavits, and knew that even Yugoslav authorities had reservations about the evidence back in the '50s -- but didn't say anything.

Justice's investigators -- who won't speak on the record -- appear to be focusing on this issue. Investigators have met with Radoslav Artukovic, interviewed the former U.S. attorney who handled the extradition and talked with the lawyer who represented the Artukovic family.

Artukovic also claims that Justice essentially "solicited" the Yugoslavs' extradition request -- which he demonstrates through an array of State Department cables detailing how Justice Department officials helped the Yugoslavs put together their extradition package. Deputy Assistant Attorney General Mark Richard, who was part of an American delegation to Yugoslavia in 1983 to discuss Artukovic, won't discuss "who knew what and when did they know it," but he maintains that Justice handled the extradition request properly.

"If we know a country is interested -- especially a country that doesn't have massive experience with what our courts wants -- we will advise them: 'Go get a person who can testify on this, go get a person who can testify on that. ...' Some of these countries may not have even expressed an interest in extradition," Richard says. "We will routinely bring it to the attention of the country."

There are few facts that Radoslav Artukovic does not insist are open to interpretation:

The police -- including the security police that ran the camps -- were at least nominally under the ministry of interior, which was run by Artukovic for 1941 to 1942. But the son and his researcher insist that accounts of the period reveal that the man who directly headed the police, Dido Kvaternik, was so powerful that he never answered to Artukovic. He went straight to the head of the government, they say.

Holocaust scholars don't buy this explanation. It's not uncommon to find no paper trail: "Whenever you get someone whose rank was minister, there is a certain remoteness from the activity and the place of death," says Raul Hilberg, author of "Destruction of the European Jews." "I am satisfied about two things: This man was a minister in a government that could be descibed as murderous, and the camps were murder operations, for all practical purposes, that were subordinated to him."

A newspaper item from Zagreb, dated April 21, 1941, announces: "The Minister of Public Safety, Dr. Artukovic, has stated ... that the Croatian government wishes to solve the Jewish problem in the same way as the German government did. The Minister added that he will strictly monitor the correct application of racial laws, soon to be adopted." Says Radoslav Artukovic: "In terms of ugly statements, I'll agree it is. But in terms of the resolution, that is an ambiguous statement."

Artukovic signed decrees implementing racial laws determining who got Aryan status, forbidding Jews to work in cultural organizations and establishments, and expropriating their property. Worst of all is a law from July 1942 that authorizes sending people to camps and authorizes the Ministry of Interior to establish these camps.

"Those decrees alone would make him ineligible to remain in the U.S.," says the Justice Department's Richard. Radoslav Artukovic argues that the concentration camp authorization law was superseded two weeks later by something of a correction, which said the ministry was not involved in the establishment of camps.

There is a photo of Artukovic saluting a group of Nazi officers. "I think that's been doctored," says Radoslav Artukovic, who's still investigating it.

There is only one thing that he cannot completely explain away. That is a speech his father gave before the Croatian State Assembly in 1942.

In it, Artukovic called Jews "one of the most dangerous international organizations." He referred to "world Jewry" as having "prepared the world revolution, so that through it the Jews could have complete mastery over all the goods of the world and all the power in the world, the Jews whom the other people had to serve as a means of their filthy profits and of its greedy, materialistic and rapacious control of the world."

It is obviously a speech that causes the son some pain. "Those words are repugnant, and I'm not going to justify them," says Radoslav Artukovic. "Would I be happy if they hadn't been spoken by my dad? You're damn right. Would I have been happy if his name hadn't been signed on some of those laws? You're damn right. ... But to extrapolate from that that he was the man responsible for setting up camps -- no way."

Both he and his researcher admit that Andrija Artukovic at least knew about the concentration camps.

"There's no way he couldn't have known," deZeng says simply. But he won't call him a war criminal. "What he's guilty of is the fact that he didn't find some way to get out."

In the son's mind, he has judged his father this way:

"If being a dirty rotten war criminal means running concentration camps, then ... he's not the guy," he insists. "If it's the speech he gave and signing legislation -- if that's your definition of rotten war criminal -- okay."

Justice Department officials speak of Radoslav Artukovic with a certain low-key sympathy.

"No one questions his motivation or his sincerity," says Richard. "I'm not sure we can ever adequately satisfy his concerns."

Another Justice official is more blunt: "Radoslav Artukovic is a very lucky man. He's lucky because he had his father for many years when he should have been in the docks. A lot of people didn't have their fathers because of Artukovic."

Ironically, Radoslav Artukovic uses practically the same words to describe the same sentiment -- for completely different reasons.

"When I speak to Croatian groups and I explain to them about what happened at the trial in Zagreb and seeing my dad alive for the last time, I say, 'You don't see me sad and I'll tell you why,' " Artukovic says. " 'I had my dad for 35 years after the war and so many of you out there didn't have a father or a mother -- they were killed by the Communists during the war. From my perspective I have a lot to be thankful for and really nothing to be sad about.' "