CONCORD, N.H. (AP) -- Two police chiefs, frustrated by what they claim is the government's failure to pursue illegal immigrants, are taking a novel approach to homeland security: using a trespassing law to arrest undocumented immigrants. W. Garrett Chamberlain pioneered the tactic in New Ipswich and Hudson chief Richard Gendron enthusiastically joined in. Both say they are helping to prevent another Sept. 11. "What do you do?" Gendron said recently. "As a law enforcement officer, I have a difficult time with someone who's not supposed to be in this country. If we're really, truly concerned about homeland security, this is...