Anti-war activist Cindy Sheehan, who protested the Iraq war by camping outside President Bush's Texas ranch, went on trial with three other women Tuesday on charges of trespassing at the U.S. Mission to the United Nations.

The women tried to deliver an anti-war petition with 70,000-plus signatures to mission officials on March 6.

Prosecutors said they were arrested after they sat down in front of the mission building, ignored police orders to leave and locked arms and legs to make it hard for police to move them.

"They were not arrested because of their message," Assistant District Attorney Caroline Han told the jury. "It was their refusal to recognize the rights of others that got them arrested."

But defense lawyers said the women did nothing wrong or illegal and that a videotape of the incident would vindicate them.

"The truth of what happened on March 6, 2006, bears no resemblance to what the prosecutor just said to you," said Robert Gottlieb, who is representing Sheehan and one other defendant. "They did nothing wrong, absolutely nothing illegal."

He said the group of 40 to 50 women had contacted a mission liaison to say they would present the petition to the mission as they had in 2005. In that instance, Gottlieb said, someone accepted the petition and the group left. This year, he said, security staff had locked the building. He said police officers in riot gear showed up and manhandled some of the women.

The four, who were protesting as part of a group called Women Say No to War, are charged with trespassing, disorderly conduct, resisting arrest and obstructing government administration. Each faces a year in jail if convicted on all charges.

Sheehan, 49, of Berkeley, Calif., lost her 24-year-old son, Army Spec. Casey Sheehan, in Iraq on April 4, 2004. She subsequently became an outspoken opponent of the war in Iraq, gaining international fame when she and others camped outside Bush's 1,600-acre ranch in Crawford, Texas, to protest the conflict.