Letting Tyler Tessier speak at Laura Wallen's news conference part of police strategy

On Monday, Tyler Tessier fought back tears as he spoke at a news conference about his missing girlfriend, Laura Wallen.

Laura Wallen had been reported missing the week before after a troubling text message was received by family members. She was a teacher at Wilde Lake High School in Columbia, Maryland and didn't show up for the first day of class, which was completely out of character, according to her family. She was also about four months pregnant with Tessier's child.

At the news conference on Monday, Tessier held hands with her parents as they listened to investigators. He listened as her father, Mark Wallen, offered a $25,000 reward for her safe return. Tessier also spoke, saying that he was praying for Laura's return and asked her for a sign to show that she was safe.

"Laura, if you are listening, it doesn't matter what's happened, it doesn't matter what type of trouble, there is nothing we can't fix together - myself and your family," Tessier said to reporters at Monday's news conference. "There are so many people, so many people that miss you, so many people who were out, who haven't slept. We haven't eaten. We are just looking or praying that you are safe."

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"Since this investigation began, Mr. Tessier has provided information to detectives that led them to suspect his involvement in this case," Montgomery County Police Chief Thomas Manger, said following the arrest.

Manger said allowing Tessier to speak at the news conference was a calculated move made by detectives and done with the approval of the victim's family.

Laura Wallen was first reported missing on Sept. 4 by her sister. Police determined that the last known financial transaction from Laura Wallen's account was a debit card purchase at the Safeway store in Olney on Sept. 2 between 8:30 p.m. and 9:30 p.m. The store's surveillance cameras showed Laura Wallen and Tessier making a purchase together.

Police say the last message from Laura Wallen's phone was to her sister on the morning Sept. 4. It was a text message detectives said Tessier admitted to sending himself.

Officers said an employee of the Gramercy Place apartment complex in Columbia located Laura Wallen's license in front of an apartment dumpster on Sept. 4. When police responded they also found Laura Wallen's vehicle, a 2011 black Ford Escape.

Between Sept. 5 and 11, detectives said they interviewed Tessier multiple times. They said in each interview, Tessier provided conflicting statements regarding Laura Wallen's disappearance. They also said he made some admissions including the fact that he was engaged to another woman. Police said Tessier also admitted that he drove Laura Wallen's vehicle to the apartment complex in Columbia, Maryland and disposed of her phone and driver's license in a dumpster, and then removed her license plate from her vehicle.

Police said they located an acquaintance of Tessier who told them that Tessier had called her and asked her to give him a ride from the apartment complex where Laura Wallen's vehicle was located. Investigators also said Tessier asked the friend to lie if police ever asked her about picking him up. Detectives also said Tessier contacted an acquaintance last Sunday night asking for a ride to Baltimore for help "to clean up a mess." The acquaintance refused to assist him.

On Sept. 13, police said they executed a search warrant on property along Prices Distillery Road in Damascus, Maryland. The property, belonging to Tessier's friend, included a farm surrounded by acres of open fields and woods.

Authorities said Tessier had been spending a lot of time at the property after Laura Wallen's reported disappearance. During the search, police said they located a freshly dug area of the ground in a field adjacent to the friend's property. It was there they said they discovered Laura Wallen's body.

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Her remains were sent to the Medical Examiner's Office in Baltimore for an autopsy to determine a cause of death. Investigators also said that a text conversation between Laura Wallen and her sister on Sept. 2 mentioned that Tessier was taking Laura Wallen on an "adventure" in the country. Police said Laura Wallen texted a photo of a field that appeared to be the same field where Laura Wallen's body was located.

Investigators said they arrested Tessier around 5:30 p.m. on Wednesday and charged him with first-degree murder. He was denied bond at his hearing in Rockville, Maryland on Thursday.

Superintendent of Howard County Public Schools, Dr. Michael J. Martirano, extended his sympathy to Laura Wallen's family on Thursday calling her an "outstanding teacher" and saying that the school community was in shock.

Martirano said grief counselors were on hand for members of the Wilde Lake High School community.

FOX 5's coverage on the disappearance of Laura Wallen:

Body of missing pregnant Maryland teacher found; boyfriend arrested

Missing pregnant teacher's family offers $25,000 reward

Vehicle of missing pregnant Maryland teacher found in Howard County

Students coming together to help in search for missing pregnant Md. high school teacher

Wilde Lake High School students hoping for safe return of missing teacher Laura Wallen

Search continues for missing pregnant Maryland teacher

Police searching for missing pregnant Maryland teacher