Sam has a heated argument over an affair he claims his wife is having with his best friend. the argument escalates and sam is overheard by the neighbors saying he wished his wife were dead. after repeatedly trying to get from sam what happened to his wife, the best friend calls the police after two days, not seeing sam's wife during that time. that samwas in a heated argument with his wife before she turned up missing establishes:

Motive, Crime of Passion and Sam is a suspect

Explanation:

Motive for killing a person will be determined by the intent to kill in terms of the circumstance surrounding at the very moment. If Sam's wife had committed the act as he claims and then she is now missing this leads to a motive if she is found dead.

A Crime of Passion may have also occurred if he was distraught by hearing the news that he was betrayed. In that instant he may have lost his judgement and committed a crime, if, in fact, she is found dead.

However if is very likely that Sam is a suspect in his wife's disappearance as he was the last person to have been with her right before he disappeared. Not only this but he was heard saying that harm may come to her which establishes that they were not on good terms.

Answer: Sam may have killed his wife.

Explanation: A suspect is one who has been accused but not yet convicted of a wrong doing. Being that Sam had an argument with his wife over an alleged affair gives Sam a motive to harm his wife. Also mentioning his wish for her to be dead makes it almost conclusive that he may have lived up to his threaten.

Finally, Sam's wife disappearance for two days after the heated argument with Sam makes him a prime suspect in his wife going missing and possible death.