I found this phone and have been using it for a while. I just use it over Wi-Fi no sim card. I need to update it to Lollipop because I failed to update it says "Update Failed". Im just aware am I going to get caught that I found the phone if I bring it to Best Buy for update? I contacted Samsung Support and they told me to bring the phone to Best Buy for update. Should I go to best buy for update? Its T-Mobile Samsung Galaxy S5
Welcome to Android Central! I would really suggest that you make an effort to return the phone to the original owner. When you found the phone, was there any identifying information available that could lead you to the owner?
Even putting aside the moral implication of having someone else's property,if it was stolen (not saying that you stole it, but maybe the theif dropped it when trying to run), and the owner reported it stolen then you would have to explain why you have stolen merchandise. Honestly, it could be a lot of hassle. Keep in mind best buy has cameras so they would have your face on record with the potentially stolen merchandise.