Liberty caps won't bruise blue, but that picture's not very good. If they look like a nipple on the top, with a tiny bump in the center of the cap, they could be. Liberty caps are usually really small, the stems might not be much bigger than a piece of grass. They can get bigger, but the caps on the ones I've found have been around finger nail size, with only two or three being bigger.
The cap should be a fairly solid opaque color. Look for gills that are quite sparse with a purple / black print. The stems of liberty caps are usually a milky to tan color, unlike regular psilocybe. They're more like bits of straw than the fibrous psilocybe stems