HPD Chief Art Acevedo said at a news conference that the sergeant took his own life at the Westside Patrol Station Friday morning.
Former Houston police officer and current consultant Mark Stephens said asking for help is especially difficult for most police officers.
"You're talking about police officers," Stephens said. "These are the people that are trained to be the helpers, not to go say, I need help."
Stephens said the stresses of the job are tremendous.
"I think what most people don't understand is that it's not a job where you go to work, you leave it there, and you come home," Stephens said. "It goes with you because you are a police officer 24/7."
Investigators do not yet know what led up to the 21-year sergeant taking his own life at work, but Chief Acevedo said it is important to find out as much as they can.
"As police officers and first responders, you see things that most people will never see," Acevedo said.
"So we need to understand what led us to this, is it an issue of something that's work related, is it an issue of mental illness, or an issue of other things."
Former League City police officer Tamara Spencer travels the country, speaking to police agencies about how to prevent suicide among officers.
"Some of the biggest red flags that we look for are officers suffering from financial loss. Relationship issues is a big one, under investigation, whether in their department or otherwise, facing termination, in some cases even retirement," Spencer said.
Stephens said that would be most helpful.
"Trying to get a stubborn cop to say, 'I need help' is probably a big part of the problem," said Stephens.
Officers in Houston who are struggling with stress or other psychological problems can call the Houston Officers Peer Assistance program at 832-200-3499 to talk with other officers about their problems.
Report a typo to the ABC13 staff