A Maryland man is behind bars after he allegedly killed the mother of his child, stuffed her body in a bin before filling it with concrete and erecting a wall to conceal his murder.

The family of Alexis Shuler reported the 29-year-old mother of three missing to Washington, D.C., police on Jan. 14 after they hadn’t heard from her in a couple of days. The family believed she was with her on-again-off-again boyfriend, 30-year-old Devontae Gray, at his home in Capitol Heights, Maryland. When police went to the house they noticed a “weird” smell but saw nothing suspicious and no sign of Shuler, a probable cause arrest affidavit obtained by local Fox affiliate WTTG said. But in the days that followed, surveillance video proved that she had been inside the home, Prince George’s County police Chief Malik Aziz told reporters at a press conference Tuesday.

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Video also reportedly showed Gray going in and out of the home on Jan. 12 and 13 carrying construction equipment such as cement, cinder blocks, chemicals and large storage containers. When police executed a search warrant on the home on Sunday, they found a newly constructed wall. Cops broke through the wall where they found a bin under a stairwell with Shuler’s body “entombed” in concrete and covered with a large amount of soil and hay, the affidavit said, according to NBC affiliate WRC. She had been shot to death, cops said.

It took some three hours to recover her body, WTOP reported.

“Evidentially some major construction work was going on inside that house,” Aziz said at the press conference.