According to the TT news agency, the prosecutor argues that the sentence handed down to the 25 year-old man does not match the severity of the conviction.
The man pleaded guilty to shooting and killing the 73 year-old jeweller, but claims he was acting in self-defence.
Three people attacked the jeweller and his wife in their home in March. The court convicted the man of manslaughter on the grounds that the jeweller was killed in a struggle after attacking the man with a knife as he was leaving the house.
Last year 54 jewellers were robbed in Sweden, five times as many as in 2004.