The Rev. Todd Pyle thought it was the perfect spot to baptize (search) 12 new members of his church. The river was calm and shallow, and there was a shaded area offshore for people to stand.

"It was a very serene place," he said. "It was special."

But officials at the Falmouth Waterfront Park (search), a public park just outside Fredericksburg, weren't pleased. They tried to break up the ceremony, claiming it might be offensive to nearby swimmers or other people using the park. Pyle was able to finish the baptism, but then he was asked to leave.

The incident has outraged free-speech advocates.

"These people are being discriminated against because of the content of their speech," said the Rev. Patrick Mahoney, who heads the Christian Defense Coalition (search). "It's one of the most egregious violations of the First Amendment I have ever seen."

Mahoney's group has threatened to file a lawsuit if the park refuses to allow future gatherings by religious groups, something for which the park admits it has no written policy.

Pyle said he chose to hold an outdoor baptism, still common in parts of the South, because his Cornerstone Baptist Church (search) in Stafford lacks an indoor baptismal pool. He said few people seemed to notice the small congregation during the 30-minute ceremony May 23.

But park officials said religious groups seeking to perform a service in the park still need to apply for a permit or else gather under a shelter or inside.

"We don't want to tread on anybody's First Amendment or constitutional rights," said Brian Robinson, director of the Fredericksburg-Stafford Park Authority. "What we try to discourage is anything not formally permitted that just sort of occurs spontaneously."

John Whitehead, director of The Rutherford Institute, a Charlottesville, Virginia-based civil liberties organization, said that's a clear violation of the church members' constitutional rights.

"Could a church have a picnic in the park and sing hymns? Of course they could," he said. "Parks have been forums since time immemorial to do these types of things."

The American Civil Liberties Union of Virginia also said in a statement: "If the park rules allow people to wade and swim in the river, then they must allow baptisms in the river."

Robinson said the park's board has formed a special committee to examine its policy and to put it in writing. If the church applies for the proper permit, he said it's "certainly possible" they would be allowed to use the river for another baptism.

Meanwhile, Pyle said he will find another place to hold outdoor baptisms.

"We're disappointed," he said. "Every single person that was baptized thanked me afterward, saying [the river] made their experience more meaningful."