U.S. District Judge Amy J. St. Eve will allow expert testimony from a psychiatrist in a lawsuit against the city regarding what a 6-year-old said he saw when he witnessed the death of his 4-year-old brother.In an order entered Thursday, St. Eve ruled that a psychiatrist who interviewed the 6-year-old following the 2005 death of his brother can testify that the boy was capable of accurately recounting what he saw when he claimed he witnessed his younger brother wrap an elastic band around his neck that led to his death.The …