Home surveillance video allowed a Butler woman to view in real time a trio of masked and armed men burglarizing her house Saturday night, police said.

The 28-year-old woman was at work when she watched images that showed the men, all carrying what appeared to be semi-automatic rifles, in her rental home in the 400 block of Brown Avenue.

No one was at the two-story house and no on one was injured. The masked and glove-wearing gunmen reportedly made off with about $1,000 in currency.

Butler Deputy Police Chief David Adam believes the unknown suspects were expecting someone to be home when they showed up shortly after 9:10 p.m. They intended to rob whoever they found there.

“To me, and it's speculation, this was a home invasion that no one was home for. I mean, who brings AR-15s to a burglary?”

Investigators suspect the men were all toting what looked like AR-15 rifles.

The woman, who lives with a female roommate, was at work when the surveillance system in the home notified her cell phone of the apparent break-in. The alert was touched off by the motion detector.

The notification instantaneously allowed her to see what was going on in real time.

Police said they believe that the suspects drove off in a Crown Victoria.

Police released video and photographic evidence of the crime scene in hopes of generating tips from the public.

Anyone with information is asked to call police at 724-287-7744, or 911.