Mr. van Gogh, 47, a distant relative of the 19th century painter Vincent van Gogh, had received death threats after the broadcast of the short TV film, "Submission." He made the movie with Ayaan Hirsi Ali, a Somali-born refugee who fled an arranged marriage and ended up in the Netherlands, where she is now a member of the Dutch Parliament.

Mr. van Gogh and Ms. Hirsi Ali, who wrote the script, have both criticized the conservative Muslim clergy for perpetuating views that are anti-women and anti-homosexual. Their 10-minute film presented the stories of four women who, while saying their prayers, describe to God the sexual and physical abuse they have suffered at the hands of the men in their lives. The actresses have Koranic verses dealing with women written on their bare skin, and some have traces of lashings painted on their bodies.

Mr. van Gogh, a prolific filmmaker, columnist and writer who dealt with a range of subjects but always mocked hypocrisy, also published a book titled "Allah Knows Better," a scathing critique of Islamic militants and clergy, whom he called woman haters. Ms. Hirsi Ali, who has lived under police protection for two years, said she and Mr. Van Gogh received death threats after the film was broadcast. "Theo did not want any police protection," she said in a telephone interview. "He often insisted on the need to preserve our freedom of speech. He said he would only report the threats to the police."

Asked if she and Mr. van Gogh had discussed the death threats, she said: "He told me, Ayaan, if they kill me, remember the rule of law has to be protected against extremists."

The man suspected of killing Mr. van Gogh fired several shots at about 8:30 a.m., then crossed the street and stabbed him several times with a knife, a police spokesman said. Witnesses told the police that the assailant then stuck a note on his victim's chest with the knife.