WASHINGTON (Reuters) - Police officials from across the country on Wednesday warned that dangerous assault weapons will flood U.S. streets if the ban on those guns expires next week but Republican congressional leaders expressed no concerns about letting the restriction lapse. "I think the will of the American people is consistent with letting it expire, and so it will expire," Senate Majority Leader Bill Frist, a Tennessee Republican, told reporters. Asked why Congress wanted to legalize the military-style weapons again when public opinion polls found broad public support for keeping them illegal, House Majority Leader Tom DeLay, a Texas...