Is Call Of Duty Modern Warfare For the DS ok for my 8 year old son to play?

I think that 8 years old is too young. Am I correct? Please help.The salesman at Gamestop said that the DS version is so much milder and different than the Wii version and XBOX version. I think that killing people desensitizes children. PLEASE HELP. Thank you. I would like an honest opinion.