Authorities said the man was distraught about his son's medical condition. His threats, say investigators, were enough to require the Harris County Sheriff's Office High Risk Operation Unit.
The standoff lasted nearly four hours. At around 10:45pm, the suspect surrendered. Police say he wasn't armed when he gave himself up.
During the standoff, the second floor at the hospital, which is where this was happening, was evacuated.
Eyewitness News spoke with one woman who was in tears outside the hospital. She said her daughter is a nurse on the second floor and came face to face with the armed man.
"She just said that she seen a gun and that she took off and tried to get help," said the mother. "It's scary. I just wanted to know where my baby was I thought she was a hostage."
Tomball police, the Texas Rangers, Harris County Precinct 4 and the Harris County Sheriff's Office were all on the scene.
During the standoff, the emergency room at the hospital was not accepting any patients. There were several ambulances set up outside, which were there to treat anyone needing urgent care.
No one was hurt.
Keeping all of those in Tomball in my thoughts and prayers.— Michael McCaul (@RepMcCaul) January 11, 2015