SALEM – A Superior Court judge set down a September trial date for Kathleen Hilton, charged with starting a deadly Lynn fire in the Highlands in 1999 that killed five people.Hilton, 61, formerly of 61 Hollingsworth St., Lynn, appeared Monday in Salem Superior Court with her long hair in a partial ponytail and wearing a green jersey, jeans and white sneakers before Judge Howard J. Whitehead.Defense lawyer Michael F. Natola told Whitehead that he and Assistant District Attorney Marsha H. Slingerland have agreed on a September trial date and asked Whitehead to confirm Sept. 8, saying an earlier trial date would not be practical because of the age of the case and locating witnesses.Whitehead scheduled a two-week trial on the court’s trial calendar, but in the interim the attorneys will meet again on April 1 to report if there could be scheduling problems with potential witnesses and because of the number of medical experts expected to testify at trial.Hilton stands charged with five counts of second-degree murder as well as a single count of arson and injury to a firefighter in the Feb. 24, 1999 triple-decker fire at 44-46 High Rock St. – allegations she has denied.The fire killed Heriberto Felicano, 34, his wife Sonia Hernandez, 32, and their two daughters, Maria, 13, and Sonia 12, as well as an 11-year-old niece Glorimar Santiago. All were trapped by the fire in their third-floor apartment.Authorities maintain that Hilton set the fire to get back at her son’s ex-girlfriend, who lived in the house with the couple’s two children, who survived the blaze, but the five others in the building died.Hilton was arrested three days after the fire. She faces up to 15 years in prison on each of the five counts of second-degree murder, if convicted.The case had been bogged down on appeals, while Natola has been battling prosecutors over which of Hilton’s statements can be used at her trial, but a statement Hilton made to a female court officer in Lynn District Court following her arraignment on March 1, 1999 has been suppressed.Hilton remains held at Framingham State Prison for Women pending the outcome of her case.