Lesley McSpadden, left, is comforted by her husband, Louis Head, after her 18-year-old son, Michael Brown was shot and killed by police in the middle of the street in Ferguson, Mo., near St. Louis on Saturday, Aug. 9, 2014.

The mother of an 18-year-old black man shot and killed in a St. Louis suburb says she doesn't understand why police didn't subdue her son with a club or Taser, and she says the policeman who shot him should be jailed.

Lesley McSpadden says her son, Michael Brown, had graduated from high school and was headed to college.

McSpadden was speaking at the site of the Saturday killing. She says police have not explained why her son was confronted by the officer. "I would like to see him fired," McSpadden said Sunday. "I would like to see him go to jail with the death penalty."