Bike was in our outdoor area of our apartment. We live on the second floor and the first floor door to our home is always locked. Perpetrator climbed our emergency landing and broke in through an open window. Took the bike (which was not locked to anything within the residence) and left out the first floor door. Helmet was found halfway down the stairs in the morning. Bike included a kryptonite U-lock. Total value of $500. We believe that we know who took the bike - there is a video circulating on Facebook in the Pilsen community group of an older african american man who was first seen wearing a blue t-shirt. As I walked out to see if the bike was around, I saw a similar appearing man wearing dark pants, a grey hoodie, and a black baseball cap wondering around the Cullerton street alley around 8:15 am. I did not approach him.