To kill two birds with one stone is an English phrase that means to achieve two goals with one action. When a terrorist group kidnapped 19-year-old Patty Hearst, they knew they were killing two birds with one stone. The group was called the SLA, and they chose to kidnap Patty Hearst because she was the granddaughter of a very rich media mogul. With Patty, they could do two things: stir up media attention and demand a lot of money.