The New York Times' Robert Worth and Nazila Fathli take a bold step for inference in their story on Iran's demonstrations: 

Unlike the other protesters reported killed on Sunday, Ali Moussavi appears to have been assassinated in a political gesture aimed at his uncle, according to Mohsen Makhmalbaf, an opposition figure based in Paris with close ties to the Moussavi family.

Mr. Moussavi was first run over by a sport utility vehicle outside his home, Mr. Makhmalbaf wrote on his Web site. Five men then emerged from the car, and one of them shot him. Government officials took the body late Sunday and warned the family not to hold a funeral, Mr. Makhmalbaf wrote.

Whoa there, big fella.  Talk about jumping to conclusions!  Sure, this looks suspicious, but I can think of several other plausible reasons for why this could have happened:

1. He was behind on his payments to bookies.... that'll teach him to bet on the New York Giants.   
2. He was in the market for an SUV that could run over people and the haggling over price got out of hand.
3. The Basij are playing one of those college assaassination games across all of Tehran, and they forgot to use their dart guns rather than real guns.
4. It was a hit and run accident, and the men in the car decided to put him out of his misery after seeing how badly wounded he was. 
5. Moussavi was really an agent for the Mossad.  The men in the SUV were really agents of the Mossad.  In  fact, 95% of the protestors in the streets of Tehran are actually agents of the Mossad, MI6, or the CIA. 

See, these are all plausible alternative storylines, and should be investigated thoroughly before calling this a "political assassination."