NEW : Attorney General Eric Holder says enough evidence existed to start a criminal investigation . Comment: Senator lauds criminal investigation launched by Department of Justice . DOJ looking into potential violations of Clean Water Act , Oil Pollution Act of 1990 and other laws . Boxer issued a statement Monday praising the criminal probe . Holder visits Gulf Coast on Tuesday to survey BP oil spill .
NEW : Attorney General Eric Holder says enough evidence existed to start a criminal investigation . Comment: Senator lauds criminal investigation launched by Department of Justice . DOJ looking into potential violations of Clean Water Act , Oil Pollution Act of 1990 and other laws . Holder visits Gulf Coast on Tuesday to survey BP oil spill .