I think if I remember correctly you have to go into the security guys metal locker but I'm not 100 percent sure. There are some walkthroughs of the game that can help you if you get stuck.
go to the left of the map and you will find a box full of grenades. collect the grenades and go to the center of the haunted house, where there is a car which you can hide behind. finally, throw the...
You can buy it at Target or Best Buy, that's where I get my Nancy Drew games.
You can also buy them online at Target.com, Bestbuy.com, or Herinteractive.com.
(: Samtacular™