The commander knew very well what that meant.
He only had this one chance. If he didn't seize this opportunity to catch or kill the Boogeyman, their team wouldn't be able to escape death when they returned.
The Elder couldn't give them several months to wait for the Boogeyman to appear again.
When Luke had been fighting the criminals, it felt like things were going to plan, but the commander had been uneasy.
As long as Luke withdrew or delayed until the police took action, the commander could just go back and wait for death.
When Luke finally stepped into the museum, the commander had been relieved.
Although this wasn't a suitable site for an ambush, much less to ambush the Boogeyman, the commander had no choice.
Most of the time, people made seemingly stupid decisions not necessarily because they themselves were stupid, but because they weren't the ones to make the decisions.