In an effort to catch more tax cheats, the state is doubling the number of reviews it is doing on people seeking tax credits on their 2007 returns. More than 1 million New Yorkers file annually for the credits, such as the Empire State Child Credit, which provides up to $330 per child to those who qualify. Many receive refunds as a result. Tom Bergin, a spokesman for the state Department of Taxation and Finance, said 147,000 tax-credit filers were targeted this year, compared with 70,000 last year, in an effort to cut down on abuses. So far, the efforts have saved the state $112 million in potentially fraudulent or undeserved credits and refunds, Bergin said. The state is hoping to save as much as $170 million by the end of the process.