When in mourning, Jewish families wear a ribbon on their clothing, on the left side which is over the heart. Sara's parents were wearing the ribbon on the right side.
When the doctor is asked if the baby would have showed any symptoms of Tay-Sachs, he answers "Nothing the parents would have noticed until about 6 months". This is untrue. Symptoms of infantile Tay-Sachs disease usually start when a child is 3-6 months old.
The Brown's were not wearing a "black piece of tape" to cover up a shirt logo. They were wearing black ribbons that act as a sign of mourning, it is part of the Jewish tradition of Shiva. Some Jewish denominations will wear a black arm band, and others wear a black ribbon on their lapel.
Andrea Brown testified on the stand that she gave her baby formula that had the crushed imipramine tablets mixed into it. She also said that before she fed the baby the drugged formula she nursed her, which is why the medical examiner also found breast milk in the baby's stomach contents.
When Benson and Stabler are interviewing the Brown couple in their home, both of them have a piece of black tape used to cover up a obvious logo on their shirts.