Recent difficult economic times have not necessarily increased general crime, but there has been a recent spike in the number of thefts, especially of wire and copper off the outsides of houses, City Hall spokeswoman Jessica Mayorga said Tuesday. New Haven Police Department Chief James Lewis explained at a Thursday press conference that while numerous factors — including decreased funding and early release of prisoners — can increase crime during an economic downturn, more family time for laid-off workers can have the opposite effect. He said overall city crime last month was down 14 percent compared to January 2008.