Chris. here are two references I have found on Cara-pils.
First
http://www.howtobrew.com/section2/chapter12-1.html
Second
Homebrewing Guide by Dave Miller
In a section under Specialty Malts, Crystal Malts.
"There is one crystal malt that stands apart from all others, both in its manufacture and use. This is
dextrin malt, also known as cara-crystal or cara-pils malt. It is stewed at higher temperature than caramel malt, which results in the creation of a large proportion of compounds called "dextrins." Dextrins are carbohydrates that are intermediate in size between starches and fermentable sugars. They are tasteless but impart
mouthfeel (body) and foam retention to the finished beer. To avoid darkening the color, dextrin malt is kilned at a low temperature. This makes it useful both in pale and darker beers."
Then under Using Specialty Malts
"Most specialty malts are best used in a mash along with pale and/or high-kilned brewers' malts. This method assures conversion of any residual starch and, in the case of naked grains, provides some husk material to give porosity to the mash. However, the dark roasted grains and caramel malts
(not dextrin malt) can be extracted in hot water to enhance the flavor and color of beers brewed from malt extract."
I have never used Cara-pils however research would suggests it needs to be mashed.