illegal search, can they do this?

here is my situation. I came home after getting a movie(gone from house aprox 15 min) and police were at my house. They had entered my house and searched it. they opened doors and in one door there were cannabis plants growing. THE DOOR WAS CLOSED AND SEALED. When I came home they told me what they found and asked for consent to search the rest of the house. I gave them consent and they found 3 grams cannabis, less than 3 grams mushrooms, and a waterpipe. The reason they said they were in my house is because supposedly there was a robbery a few doors away(this was during thanksgiving break in a college town) and they saw a "ladder" leaning against the wall of my house. There was also a screen cut out of the window. They said this looked like a robbery so they knocked and I wasn't home so they entered.
Here are the circumstances:
my lights were on,
the front door was unlocked,
my car was in the back driveway,
i have a 5 month old pitbull(to which the officer exclaimed he almost didn't enter my house because of the dog),
the "ladder" was a couple of 2x4's used to prop up the air conditioner and that is also why the screen was cut(for the air conditioner),
the officers did not inspect the window that was supposedly broken into-I know this because it was one of three windows right next to each other and they are covered by a large tapestry which is held in place by several items that were still in place when I walked in,
the officer walked past the window in order to enter the room with the plants,
the room is in the back of the house-the officer went thru a living room, a den, a kitchen, and into a hallway to get to the grow room.
my questions are among many-did they have a right to enter my house? and If it is proven the plants were found illegally then would I still be charged for the evidence found after I gave consent?
You could not see light thru the windows outside the grow room and the door was shut with VERY LITTLE if any light showing thru the crack of the door jamb.

I am a law school graduate. What I offer is mere information, not to be construed as forming an attorney client relationship.

What you are asking to get off on a technicality. I hate to admit it, but it sounds like you just might be able to negate all evidence they found. Problem is though that you gave them consent when you returned.


So, my opinion is this: explain all of this to a criminal defense attorney in your state and go from there.