On Sunday, Patti Saylor kept thinking of Mother’s Day last year, the last one she spent with her son, Robert Ethan Saylor, before he died earlier this year while in the custody of three off-duty Frederick County sheriff’s deputies at a movie theater. Saylor of New Market said she was in Frederick Memorial Hospital during Mother’s Day weekend last year to be checked out for possible heart trouble. Ethan, who had Down syndrome, wanted to stay with her because he was worried, she said.