What was the remote control really for a bomb? how did he know that she died?

If you can explain better what you are referring to, you will probably get some answers!

I think you're referring to Mr. Monk and the Astronaut. The bomb was actually a garage door opener hidden in a doll that was sent to the victim while the guy was in space. He had drugged her three days before and rigged a rope to the door opener so that it would hang her when the doll was delivered. I hope this answers your questions.