What will i be possibily charged with?

cops are trying get me with theft by deception and what what will i be charged with in pennsylvania? the total of the item was 650.00 and am totally innocent, i know some will say get an attorney i have one. and other questions i have is if i write a statement and was not read my rights can they bring that statement up in court? and are they alowed to question a person harshly in front of a child when the child had no involvement?