Lawyers for Dorothy June Brown in her fraud trial presented testimony from a forensics expert Tuesday that aimed to undermine the government's claim that documents were backdated to benefit her management firms.

Louis Cinquanto, chief operations officer at Cornerstone Legal Consultants, told a federal jury that data embedded in a computer document cannot definitively show when a document was created. Creation times for Microsoft Word documents can be altered if they are e-mailed, he said.

During cross-examination, however, Cinquanto said he did not know whether the documents he reviewed for Brown and her codefendants had been e-mailed.

And he acknowledged that the information about creation dates gleaned from several of those documents do not conflict - and may support - the sworn testimony of witnesses who have said they created and backdated contracts with Brown's management companies, board meeting minutes and resolutions.

Also on Tuesday, Meghan Allshouse, who taught science at Brown's first charter and is chief executive at another, described the schools' academics at length.

Allshouse said a detailed curriculum, parental involvement and homework requirements had produced top test scores and high levels of student achievement.

Brown is charged with defrauding the charters she founded of $6.7 million and conspiring with two former administrators to obstruct justice by orchestrating a cover-up.

The trial resumes Wednesday in U.S. District Court in Philadelphia.