LYNN – Her sore back forced Daisy Colon to abandon a daily drive to Lynn to talk to police about her missing son, but she holds out hope she can see Giovanni start kindergarten on Sept. 8.The 5-year-old is enrolled in the Samuel Adams School in East Boston but Giovanni has been missing since the weekend of Aug. 16. Colon says she dropped him off with his father, Ernesto Gonzalez, on Aug. 15.Gonzalez told police he had not seen the boy since the previous weekend. He pleaded innocent to child endangerment charges and remains held on $500,000 cash bail.In the 10 days since Giovanni’s disappearance, Colon has drawn strength from her mother, Luz, who traveled from Puerto Rico to Boston to help her daughter, and other relatives.”I miss him. I’m just waiting for him to come back,” she said, adding she is helping police solicit help from anyone who might have driven downtown in the vicinity of Gonzalez’ Brightwood Terrace apartment on the days Giovanni was with him.”I keep praying,” she said.Colon said police assure her they are following up on every piece of information passed on to them regarding Giovanni. Searchers combed downtown streets and buildings last weekend and have searched St. Mary’s and Pine Grove cemeteries and Flax Pond.They also took possession of Dumpsters and trash barrels located on Brightwood Terrace and nearby streets, including Rogers Avenue.”They requested we move two Dumpsters to an investigative area and we did,” said Casella Waste Services spokesperson Joe Fusco.Colon traveled every day last week from East Boston to Lynn to meet with police. Back pain forces her to walk with a cane and she decided this week to suspend the trips after the pain worsened.She and Gonzalez separated when Giovanni was 2. They were living on Pattys Way and Gonzalez moved to 3 Light St. Brightwood Terrace neighbor Kim Whitford said Gonzalez moved into 2 Brightwood six months ago.Prosecutors Tuesday said they have yet to identify the source of blood found on a mop head and cleaning bottle cap. Those items were taken from Gonzalez’ apartment Aug. 18 after police executed a search of the apartment.Police sought and received another warrant on Aug. 20 to search the apartment, in the words of the warrant application, for “blood, blood stains, physiological fluids and matter visible and non-visible.”