Autopsy Of Murdered Pregnant Teacher Reveals She Was Shot In The Back Of The Head

BALTIMORE (WJZ) — The boyfriend of a pregnant Maryland teacher who was missing for more than a week before being found dead in a shallow grave on a Damascus property Wednesday appeared in court Thursday.

Tyler Tessier, charged with first degree murder in Laura Wallen's slaying, was ordered held without bond.

Wallen was four months pregnant.

Tessier was arrested Wednesday afternoon. Police are waiting for autopsy results on the cause of death.

RELATED: Last Texts From Slain Teacher Said Boyfriend Was Taking Her On 'Adventure'

After Tessier's bond hearing Thursday, Wallen's father said his daughter is at peace with God, but he lashed out at her accused killer.

"He is a monster and he is a liar," Mark Wallen said. "He has been deceiving and lying their entire existence and their relationship was the only thing that Laura and her family ever fought about."

The Wallen family also revealed how difficult it was to sit next to Tessier during a press conference police arranged to see if Tessier would crack.

"It was a calculated decision made by detectives to have Tessier attend the event and speak," Manger said. "It was done with the approval and knowledge of the victim's family."

"It was absolutely the hardest thing that my wife could do would be to sit next to him and hold his hand," Mark Wallen said. "And she had to hold his hands with two hands because she was shaking so badly."

Tessier, already a person of interest in the case at that time, cried through a brief statement at that press conference.

"We haven't slept, we haven't eaten, we're just looking and we're praying that you're safe," Tessier said.

Detectives say Wallen had been dead for more than a week by the time that press conference was held. They pieced together her final hours using texts she'd sent her sister, telling her Tessier had taken her to a field in the country. That's where police found her body in a shallow grave.

Police say that Wallen was shot in the back of her head according to the autopsy. Police are now looking for a weapon.

Police say after Tessier killed Wallen, he pretended to be her, sending her sister texts that the baby had a different father.

As for the motive, prosecutors now say Tessier was involved in a love triangle, promising to marry both Wallen and another woman he was seeing.

"He lied to my face, when I asked him about the other girl," Mark Wallen said.

WJZ asked the State's Attorney today whether he planned to charge Tessier with the murder of the unborn child. He said they're researching it, but the law and circumstances surrounding this case are complicated, so he believes that's highly unlikely.

At Wilde Lake High School, where Wallen was a teacher, the word had already gone out on social media this morning for students to wear black to reflect their sorrow about Wallen's death.

Howard County schools superintendent Dr. Michael Martirano spoke before classes began.

"There is no normalcy right now for us," he said. "Right now we are managing the immediacy of the school day. This is shocking. Many of our students are coming here today who've not heard about this. And we want to respond to those needs first. As the day progresses, we'll be looking at ways to honor her, to celebrate her life. And make certain that there's an opportunity for us to grieve."

The grieving had already begun Wednesday night when a planned vigil turned into an impromptu memorial.

"Why?" one student asked, before bursting into tears in front of the microphone. "Like why? Like, what motivated you... like how could you be possessed by so much hate?"

"The most important thing right now is to convey empathy, to listen, to convey care and compassion and to try to help young people make sense out of it, and as I've said several times, these are different things to make sense out of for us as adults," Dr. Martirano said.

He couldn't say how many people would be arriving to help the students, be did say he'd bring in as many people as necessary.

Follow @CBSBaltimore on Twitter and like WJZ-TV | CBS Baltimore on Facebook