Trail cams. More spendy ones are live wireless.
Wireless cams, fake cams, and home power or solar-powered motion-activated spotlights all work well together. But in this case, they used the classic “female needs help” ruse to get the door open (and her foot in the door.) Your family REALLY needs to understand how this ruse works, to be on their guard against it. Most people instinctively trust a female at the door, and will open it. DANGER!!!! Talk through the door. And try to clear any visibility shadows back away from the door, so the gang can’t be a few feet away, but out of sight. Even fake video cameras can be a big help there.