MIAMI (AP) — It's virtually certain that BP and other companies involved in the Gulf of Mexico oil spill will face criminal charges and civil penalties that could translate into hundreds of millions of dollars in fines. But for any company executives or workers to be indicted individually, legal experts say the Justice Department will have to find evidence they orchestrated a coverup, destroyed key documents or lied to government agents.

"One of the issues that government investigators are going to be focused on is whether individuals from BP and the other companies have been completely forthright," said David Uhlmann, a University of Michigan law professor who spent seven years as chief of the Justice Department's environmental crimes section. "The coverup is often more serious than the crime, at least in terms of the charges sought."

Prosecutors could seek serious jail time — five years or more — if they charge anyone with obstruction of justice, making false statements to the FBI or other U.S. officials or conspiracy to hinder a federal probe. But there's got to be evidence that a person was aware of the wrongdoing, well beyond mere negligence or incompetence, experts said.

"You've got to be really bad, far beyond the norm of ongoing carelessness," said Robert Wiygul, a Mississippi attorney who, after the disaster, sued the U.S. Minerals Management Service over its regulation of offshore drilling. "The standard of proof is much higher."

The investigation announced by Attorney General Eric Holder is being run by the Justice Department's environmental crimes section in Washington along with U.S. attorneys' offices in Florida, Alabama, Mississippi, Louisiana and Texas. The probe initially focuses on BP, rig owner Transocean Ltd. and Halliburton Co., which handled the well cementing job prior to the deadly April 20 explosion that destroyed the Deepwater Horizon rig.

Justice Department officials confirmed Wednesday that the three companies have each been told in writing to preserve all documents and records related to the events leading up to the explosion, the spill and its aftermath, which is common practice in such cases. BP, Halliburton and Transocean each issued statements Wednesday to The Associated Press saying they are cooperating with all U.S. agencies, including the Justice Department.

But a criminal investigation could also hinder the companies' work with the government in cleaning up the spill and may make workers concerned about possible jail time more wary about speaking with U.S. officials. Already one BP official, Deepwater Horizon well site leader Robert Kaluza, invoked his Fifth Amendment right against self-incrimination in refusing to testify before a congressional committee.

"People may be petrified they wind up perjuring themselves if they don't tell everything," said Daniel Becnel, who is representing several people suing BP and the other companies over the oil spill.

The most likely source of criminal prosecution are federal Clean Water Act and the Refuse Act, both of which were used following the 1989 Exxon Valdez oil spill in Alaska. Prosecutors brought the charges against Exxon as a corporation and not against any company officials, eventually resulting in guilty pleas to misdemeanors and payment by the oil giant of a relatively minimal $125 million in fines and restitution.

Individuals can also be charged under the Clean Water Act, including one section that carries a maximum 15-year prison term for any "responsible corporate officer" who knowingly places another person in danger. Eleven workers were killed on the Deepwater Horizon, and experts said investigators will be looking closely at who knew what, and when.

"There's going to be some corporate officers who are biting their fingernails," said David Guest, a Tallahassee, Fla.-based attorney for the Earthjustice environmental group.

Charges and civil penalties can also be brought under a variety of environmental protection laws, including the Oil Pollution Act, the Endangered Species Act, the Migratory Bird Treaty Act and the Marine Mammal Protection Act. Each contains penalties that can reach tens of thousands of dollars per violation, with each passing day often constituting a new violation.

"There is really nothing off the table at this point," Holder said in announcing the probe.

The mere presence of oil-covered birds, dead dolphins and oil in the water makes it almost certain BP and the others will face charges under one or more of those laws, legal experts said.

"I don't think you open an investigation like this, with such fanfare, unless you felt pretty sure of things," Wiygul said. "If they didn't see some pretty significant fire besides the smoke, I don't think you would see this kind of high-profile introduction."

In addition to the criminal case, BP, Transocean, Halliburton and other companies linked to the Deepwater Horizon are named in more than 130 lawsuits seeking damages because of the spill's disruption of fishing, tourism and other economic activity across the Gulf Coast.


Associated Press writers Michael Kunzelman in New Orleans and Pete Yost in Washington contributed to this story.