Recorded last words

Try solving this challenging riddle: A man was found on the floor dead with a cassette recorder in one hand and a gun in the other. When the police arrive at the scene they pressed play on the recorder. It was the man’s voice. He said, “I have nothing else to live for. I can’t go on,” followed by the sound of a gunshot. After listening, the police knew that this was a murder, not a suicide. How? Speaking of last words, these are some memorable last words from iconic people.
Answer

If the dead man had killed himself, he wouldn’t have been able to press the reverse button on the cassette recorder.
Guilty in court

A woman was in court for killing her husband. She said she wasn’t guilty and that she dearly missed him. In the closing statement, the woman’s lawyer stands up and says, “Her husband was just missing. Everyone, look at the doors. He’s going to walk through them in about 30 seconds.”
The entire jury stares at the doors waiting for waiting for this woman’s husband to walk through the doors. The lawyer and the woman stare at the jury.
The lawyer concludes by saying, “See! If you were so sure she killed her husband, you wouldn’t be watching that door!”
The jury immediately gave a guilty verdict. Why?