The boyfriend of a slain pregnant high school teacher in Maryland was reportedly indicted Thursday on one count of murder. A hearing is scheduled for October 20.
Police found Wallen's body buried in a shallow grave in Damascus on September 13.
Allen Wolf, Tessier's public defender, said his client is innocent.
Police arrested Tessier Sept. 13 on charges of first-degree murder, altering physical evidence and making a false statement to an officer.
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Wallen disappeared over Labor Day weekend.
After his arrest, Tessier admitted to police that he was engaged to another woman at the same time that he was dating Wallen.
Prosecutors believe the love triangle between Wallen, Tessier and his fiance was the probable motive behind the killing.
Police say Tessier admitted to certain aspects of the case, including driving Wallen's vehicle to Columbia and disposing of her driver's license and iPhone. According to court documents, Tessier sent messages to them pretending to be Wallen, stating that she was anxious that somebody else was the father. She was four months pregnant with Tessier's baby. Her body was found later in a shallow grave in the Damascus area.