KANSAS CITY, Kan. -- It's been 25 years since a man climbed through an unlocked sliding door of an Olathe, Kan., home, beat a 12-year-old girl death with a hammer and kidnapped her 17-year-old sister.

Kelly Duffield was raped and killed, her body found 10 days later. Duffield's 15-year-old son Paul also was attacked and suffered serious injuries.

On Monday, the victims' mother, Carole Duffield, asked the Kansas Parole Board to keep her children's attacker, Michael Cade, behind bars.

"This man should never ever -- and I use the term man loosely -- but this monster should never see the light of day again," she said.

Duffield told The Kansas City Star that she doesn't think the 46-year-old Cade will win parole, but adds that there's a part of her that always worries that he might.

Ten years ago, Cade's first request for parole was rejected. He makes his second appeal before the board early next month. Monday, Duffield spoke before the parole board at a public comment session in Kansas City, Kan.