Texas Penal Code (2011)
Chapter 9. Justifications Excluding Criminal Responsibility
SUBCHAPTER D. PROTECTION OF PROPERTY
Sec. 9.44. USE OF DEVICE TO PROTECT PROPERTY.
The justification afforded by Sections 9.41 and 9.43 applies to the use of a device to protect land or tangible, movable property if:
(1) the device is not designed to cause, or known by the actor to create a substantial risk of causing, death or serious bodily injury; and
(2) use of the device is reasonable under all the circumstances as the actor reasonably believes them to be when he installs the device.