Birmingham police were looking for a person of interest following the discovery of three suspicious packages.   All the packages were found downtown, near the Massey building, the Daniel building, and across from the YMCA.   Police said they wanted to speak with Vera Quarles, a transient, who may be living around Southside.   Her name was associated with the packages, police said.   Police shut down several blocks for hours during the investigation.    No charges were expected, as the packages  were contained nothing dangerous, mostly letters, police said.