BALTIMORE (WJZ) -- Details of an ever-changing story are emerging in the murder of Columbia high school teacher Laura Wallen.
This new information is coming from prosecution documents detailing what Tyler Tessier, who is charged with murdering Wallen last September, told police shortly after his arrest.
Laura Wallen, who was four months pregnant with Tessier's child, was found in a shallow grave in a Montgomery County field after being shot execution-style in the head.
In his police interview, Tessier said Wallen was worried her pregnancy would cost her her job at Wilde Lake High School. He said she urged him to help her disappear.
Tessier then changed that story, saying the couple had been kidnapped, taken to the field, and Wallen was shot and killed. Tessier said he was able to escape.
Then came a third version. Tessier claimed the couple were having an argument at her home, when Wallen accidentally hit her head on a porch post and collapsed.
Thinking she was dead, Tessier buried her in the field, but then feared he had buried her alive. Tessier says he shot her once in the back of the head to ensure she wasn't suffering.
Prosecutors have their own ideas, including the possibility that Tessier's relationship with another woman led to the killing of Wallen to keep the two women from meeting.
Tessier's murder trial is scheduled to begin in September.
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