1 Take Cover/Concealment behind the nearest object providing such. Maintain a silent presence until you has assesed the intruders intent and / or physical capabilities and do a very quick threat assessment ; do they have a weapon visible? / are they constantly reaching behind their back to tuck something in, are they reaching oddly for something in a pocket or IWB type style etc.
2 Draw down upon intruder regardless of visible intent. Make your presence known, and that theirs is not. Instruct accordingly in a commanding and authoritive voice. Provide clear instruction, avoid screaming at them
3 in the event of any suspicious or not visible hands ( which shouldve been demanded in step 2 ) begin to prepare a disabling shot, that could very quickly be turned into a fatal shot. Such as should to chest adjustment.
4 allow them an opportunity to RUN and nothing else. any reaching into pockets, slow walking, walking backwards, or insivisble hands should be taken as a further threat as the target still appears confrontational. maintain and repeat steps 2 through 3 until situation is resolved or WCS turns worse.
5 proceed accordingly. ALWAYS 'walk your target out' while ADS in a logical location. maintain visual contact until they are well gone, or seemingly subdued ( laying on the floor with their hands interlocked behind their head is clearly not going to be a situation where preparing a fatal shot is logical )
6 yell to others inside for a 911 call, or do it yourself if you havnt already.
be sure to inform 911 of your description, and your current situation ; INC. the weapon you possess , your current position in regards to the neighbourhood etc. Thus providing the FOS the ability to be expecting you, and not precieving you as an additional threat.
--- the list i have provided is based upon a rapid personal assessment done according to the information you have provided in combination with basic tactical skills ; with a pinch of inexperience measure.
unfortunately, the only way true preparedness can be obtained is by training and practice. Words alone will never prepare you, skill wise or mentally for this situation.
THE SILENT TYPE