My exterminator told me they are hard to identify. THeir markings aren't pronounced and they are usually so small it's hard to tell.
That is true. I killed a large brown spider in Dec in the back of my gal's pickup bed. I checked all the spiderology and could not locate a comparison.
My thinking is this, if it has legs, is tiny and is uninvited, kill it!
Sanitize everything around the damn thing!
Because of their small size, the easiest way to identify them is by looking at their legs.
The Brown recluse's front and rear sets of legs are extraordinarily long when compared to the middle sets.
Just about every member of our household has had a brown recluse bite at one time or another, although thankfully no one had a reaction as severe as the one shown above.