San Antonio Homeowner's Guide -
Windows and sliding doors
Windows and sliding doors:
Window locks can be easily pried open, and sliding glass doors or windows
can be lifted out of their tracks. Therefore, secondary locks should
be installed on all windows and self-tapping screws in the upper track
allow the door or window to slide into place. A square-edged length
of wood placed in the bottom track will resist lateral forcing. Most
windows can be pinned for security. Drill a 3/16" hole on a slight
downward slant though the inside window frame and halfway into the outside
frame. A nail or pin can then be placed in the hole to secure the window.