Wickersham said Green told police he sent the e-mails out of "boredom."

In 2002, Green opened two credit card accounts in Shelby Township, Mich., using the Social Security numbers he had stolen, and police there filed charges against him, Wickersham said. However, Wickersham said he didn't think Green did anything similar in Macomb County.

After finding Green in the library, police searched his house, Wickersham said. Police seized his computers, analyzed them and determined that he was not engaged in any additional criminal activity. They presented the case to the prosecutor's office and were granted a warrant to arrest Green, Wickersham said.

Green was arraigned Monday, when his family posted 10 percent of the bond. A probable-cause hearing will be held in a few weeks, Wickersham said.

GM spokeswoman Geri Lama confirmed Wickersham's account of Green's activities.