Several former clients, including Baltimore City Council President Bernard "Jack" Young, said after the robocalls were traced to Henson by The Baltimore Sun that they would no longer work with him.
The indictment accuses Henson of tapping resources from his Democratic clients when designing the voter suppression strategy for Ehrlich.
Two call lists were merged, according to court papers. One was originally created for Deborah Claridy's failed bid for Baltimore sheriff in 2010, prosecutors said. That campaign paid one of Henson's companies $35,000.
The Prince George's County phone numbers came from Marilynn Bland's campaign for clerk of the court. A slate associated with that effort paid a Henson firm $38,000 last year.
According to the indictment, Henson met with top Ehrlich aides last summer and outlined a voter suppression strategy in 472 precincts. At that time, the Ehrlich campaign decided it would be too expensive.
But the idea apparently re-emerged. The indictment describes a hectic "war room" at Ehrlich headquarters on Election Day. Starting in the early afternoon, there was a flurry of phone calls between Henson and Schurick.
In the late afternoon, Henson associate Rhonda Russell recorded a 25-second "test" message and sent it to Schurick and Massoni, the indictment states.
Schurick accessed his voice mail just after the test message was sent to him, according to the indictment. Minutes later, the calls started going out to 112,544 phone numbers.
Schurick is also charged with obstructing justice for failing to provide prosecutors with a complete copy of "The Schurick Doctrine" memo described in the indictment.
William H. "Billy" Murphy Jr., another member of Schurick's defense team and a friend of Ehrlich and Schurick, predicted his client would be "completely exonerated."
"I have respected and worked closely with my good friend Paul Schurick since his involvement in Governor Schaefer's administration, and I know he would never do any of these things," Murphy said.
An arraignment for the criminal charges in Baltimore Circuit Court is scheduled for next month, prosecutors said. Henson and Schurick will be ordered to court via a criminal summons, and therefore were not arrested Thursday.
Henson and his associate Russell also face a multimillion-dollar federal civil complaint filed in November by Maryland Attorney General Douglas F. Gansler. An attorney for the U.S. Department of Justice Civil Division also is listed as a plaintiff in the case.
Gansler alleges that the robocalls were intended to suppress and intimidate voters in predominantly African-American, Democratic neighborhoods. If found to be violations, each of the 112,000 calls would carry a $500 fine.
On May 25, U.S. District Judge Catherine C. Blake denied Henson's motion to dismiss the civil case. The court is still considering a defense motion to stay the proceedings pending the outcome of any criminal cases.
Henson defense attorney Smith argued that going to court in the civil case would violate the witnesses' protection from self-incrimination.
Gansler's office, in a response to that motion filed June 2, argued that "defendants are asserting this privilege even though no criminal actions have commenced." David Paulson, a Gansler spokesman, said the two cases are "separate and unrelated."
Text of the robocall recording
"Hello. I'm calling to let everyone know that Governor O'Malley and President Obama have been successful. Our goals have been met. The polls were correct, and we took it back. We're OK. Relax. Everything's fine. The only thing left is to watch it on TV tonight. Congratulations, and thank you."
[From court papers filed in civil and criminal complaints]