Milwaukee, USA -- The Living Church of God congregation that met weekly in a Brookfield, Wis., hotel ballroom -- where a member went on a deadly shooting rampage March 12 -- is one of scores of American religious groups that gather regularly in hotels, schools and movie theaters.
Religious scholars say that while no definitive census of similar groups exists, every major American city hosts regular meetings of people looking for spiritual guidance outside of the traditional brick-and-mortar church.
Because they don't have their own buildings for outsiders to see, the groups usually remain anonymous until an event like the recent shootings brings them attention.
Terry Ratzmann, described as quiet and devout, opened fire on a group of men, women and children attending a regular Saturday service, killing eight people -- including himself and the church leader -- and seriously wounding four others at the Sheraton Milwaukee Brookfield Hotel.
There is no shortage of religious people who meet in spaces more often affiliated with secular activities, scholars say.
"It's entirely possible that indigenous Protestant groups of Americans can meet anywhere and nowhere," said Harold Bloom, a Yale University professor and the author of "The American Religion: The Emergence of the Post-Christian Nation," a book about religious groups formed in the United States.
"There always has been a radically Protestant tradition that holds that the only temple in the end is the pure and upright heart of the Protestant believer."
According to J. Gordon Melton, the director of the Institute for the Study of American Religion in Santa Barbara, there are about 100 different affiliated religious groups that meet in private homes or rented spaces.
The largest of those groups was once the Worldwide Church of God, which in the early 1990s splintered into three main groups, including the Living Church of God that met March 12 in Brookfield.
While many religious groups that meet in hotels and schools do so because they cannot afford to own a permanent facility, others do so based on their own particular doctrine.
Members of the Worldwide Church of God and its primary descendants -- the Living Church of God, the Philadelphia Church of God and the United Church of God -- believe their resources are better spent on publishing literature spreading their religious message than on buildings.
All three publish and distribute for free books and magazines with names like "The Good News," aiming to spread their message.
"They'll say it's not their duty to get a response, it's their duty to get the word out," Melton said.
Other groups hold meetings in rented facilities because they try to appeal to people seeking an unconventional religious experience, said Nancy T. Ammerman, a Boston University sociology of religion professor who is the president of the Society for the Scientific Study of Religion.
"They're trying to attract people who want to meet someplace that doesn't look like a traditional church building," Ammerman said.
One of the largest nationwide religious groups to rent space outside of churches is what remains of the International Church of Christ. The national organization is officially dissolved but maintains a Web site with loosely affiliated branches, including the Milwaukee Church of Christ, which meets Wednesdays and Sundays on the city's north side.
The nondenominational church, which has a Sunday attendance of 450 people, is able to fund projects at home and abroad because it doesn't have the overhead costs of a traditional church, said James Hamann, the group's lead evangelist.
"Because we don't have the huge expense of a mortgage and all that comes with it, it enables us to have an extra minister to meet some of the life needs that people have," Hamann said.
Some religious groups that begin meeting in private homes and rented space do so only until they can raise enough money to purchase or build their own church.
The nondenominational Elmbrook Church began in 1957 as a confederation of five Waukesha County families that met in its members' homes, and by the 1970s had outgrown two facilities and was holding services at the old Ruby Isle movie theater in Brookfield.
It now has a 300,000-square-foot facility on 40 acres in the Town of Brookfield and has spawned eight churches in southeastern Wisconsin.
Elmbrook's spinoff churches begin by meeting in schools until the congregation is established enough to raise money to buy or build its own facility.
Today the Southbrook Church in Franklin is the only one still meeting in rented public schools, according to Dick Robinson, Elmbrook's senior associate pastor.
"When a church begins you do things that you would do in a church, it's just the families meeting together," Elmbrook's senior associate pastor Dick Robinson said. "As more and more people meet together you look for someplace to go."