In Spectre, Mr. Hinx goes to Mr. White's house to terminate him. However, Bond approaches him before he did, and Mr. White shot himself. There was a camera inside the house, which is used by Spectre to keep an eye on Mr. White. They knew he is already dead (as shown later when Bond visits Spectre's facility in the desert). Then why does Mr. Hinx go to his house? Did Mr. Hinx not know he is already dead?
The camera does not belong to Spectre, it is Mr. White's camera. They do not know where he is (or don't care) until after James has already visited.
He uses it to keep an eye on the ground floor of his house, as he is incredibly paranoid at this point (having left Spectre he was expecting them to try to assassinate him.) This is why he was hiding downstairs behind a secret door, which was subsequently found by James.
After their conversation about finding and protecting Mr. White's daughter Madeleine and then his suicide, James leaves to fulfill his promise.
Mr. Hinx later tracks down Mr. White's house and discovers that he is dead. He then easily finds the recording equipment that he had used. He uses the video of James and Mr. White's conversation to also find Madeleine where she works.
So Spectre only found out Mr. White was dead after Hinx finds him, and uses Mr. White's camera to get the video to find out Bond and Madeleine's location.