Obama's vow of justice drove down the Dow as BP launched a new siphoning effort.
WASHINGTON - Striking an increasingly aggressive posture as the Deepwater Horizon disaster enters its second month, the Obama administration said Tuesday that it had begun civil and criminal investigations into the massive oil spill in the Gulf of Mexico.
"If we find evidence of illegal behavior, we will be extremely forceful in our response," Attorney General Eric Holder said in New Orleans after viewing damage caused by the widening spill, which he described as "heartbreaking to see."
Holder said he believes there is "sufficient evidence for a criminal investigation" into the spill, which has halted fishing in nearly a third of the Gulf's federal waters, tainted shorelines and spread across an area with a 200-mile radius in the Gulf of Mexico.
Justice Department lawyers are examining whether the companies that owned and operated the Deepwater Horizon rig in the Gulf, which include BP and Transocean Ltd., violated an array of federal statutes that contain criminal and civil penalties, including the Clean Water Act and the Endangered Species Act.
On Wall Street, the Dow Jones industrial average fell 120 points shortly after Holder's announcement as energy stocks dropped. BP lost 15 percent of its market value.
After six weeks of failures to block the well or divert the oil, BP was using robotic machines to carve into the twisted appendages of the crippled well. The latest attempt involved using tools resembling an oversized deli slicer and garden shears to break away the broken riser pipe so engineers can then position a cap over the well's opening.
Even if it succeeds, it will temporarily increase the flow of an already massive leak by 20 percent -- at least 100,000 gallons more a day.
"It is an engineer's nightmare," said Ed Overton, a Louisiana State University professor of environmental sciences. "They're trying to fit a 21-inch cap over a 20-inch pipe a mile away ... using little robots."
The solution that offers the best prospect of halting the ceaseless flow of oil involves the digging of several relief wells, something likely not to be completed until August.
"We're not talking about capping the well anymore. We're talking about containing the well," said Coast Guard Adm. Thad Allen, the spill's national incident commander.
BP Chief Operating Officer Doug Suttles said Tuesday on Fox News Channel, "We need to let the investigations run their course, and they'll find what they find and we'll deal with that when they find it."
The Deepwater rig explosion in April killed 11 workers and has pumped an estimated 21 million to 44 million gallons of oil into the Gulf. On Tuesday, oil reached the borders of Mississippi for the first time after already reaching the shores of Louisiana and Alabama.
Obama pledges 'justice'
As Holder toured the oil-stained Louisiana Delta Tuesday, President Obama at the White House pledged to bring "those responsible" for the spill "to justice."
The president met Tuesday with members of a commission he formed aimed at preventing a similar disaster. He appeared in the Rose Garden with the commission's co-chairs, former Democratic Sen. Bob Graham of Florida and William K. Reilly, who headed the Environmental Protection Agency under former Republican President George H.W. Bush.
Obama said he is expecting a report from them in six months. He said that if laws are insufficient, they'll be changed. He said that if government oversight wasn't tough enough, that will change, too.
During the meeting in the Oval Office, the president was adamant that the government and the industry had to find a way to make offshore drilling safe because the nation needs the oil, and stressed to Reilly and Graham that that was part of their charge, according to people familiar with the meeting.
Holder said the laws under review for the criminal and civil investigations include the Clean Water Act, the Oil Pollution Act of 1990, the Migratory Bird Treaty Act and the Endangered Species Act. He said the government would pursue criminal charges "if warranted," a caveat he did not include for civil action.
Washington lawyer Stan Brand said that two likely criminal law theories the Justice Department will pursue are false statements to the Interior Department and obstruction by failing to produce evidence to investigators.
The Associated Press and Washington Post contributed to this report.