How did the Murphy's find out about Murph's death in Chapter 11?

In December a black sedan drove through town to the Murphy's place. The Murphy's had been called by a friend letting them know that the men were coming. They watched from the kitchen window as the men stopped in the driveway. When the men got out of the car, Mr. Murphy went outside through the back door. Mrs. Murphy did not answer the door, so the men gently broke the door open. They told her that Murphy had died. Then they left a card with a phone number that she could call if she had questions.