Since evidence of pervasive foreclosure improprieties emerged, state officials have mostly brought civil suits against the institutions and law firms that filed the fraudulent documents. Individuals in Nevada, for example, have been charged with notary fraud, but beyond that matter, criminal cases arising from foreclosure practices have been uncommon.

The Missouri grand jury found that the person whose name appeared on 68 documents executed on behalf of a lender — someone named Linda Green — was not the person who had signed the papers. The documents were submitted to the Boone County recorder of deeds as though they were genuine, Mr. Koster said.

A recent civil lawsuit against Lender Processing by the attorney general of Nevada found that former workers at one of its divisions had described their work as “surrogate signers.” One worker who was quoted in the complaint said she had been paid $11 an hour and told that her job was “to sign somebody else’s signature on documents.” The person said she had signed roughly 2,000 documents a day for months, according to the lawsuit.

In addition to deed releases, DocX surrogate signers routinely executed assignments of mortgage, which reflect changes in ownership.

The indictment is only the latest legal assault on the company and its parent, Lender Processing. In August 2011, American Home Mortgage Servicing, a large loan servicer, sued Lender Processing contending that more than 30,000 residential mortgages that it had handled across the country contained “improper execution, notarization and recording of assignments of mortgage.” DocX executed such paperwork for American Home from April 2008 through November 2009, the lawsuit said.

Last April, Lender Processing signed a consent order with the nation’s top financial regulators, agreeing to remediate improperly executed mortgage documents and to correct its default business practices. Michelle Kersch, a Lender Processing spokeswoman, said recently that the company now executed documents “with stringent controls in place” to ensure compliance with all rules.