Police Report Known Facts Back Theory, Cite Law: Fly Items To FBI Laboratory The emphasis in the Y. W. C. A. blast probe here yesterday turned to a murder investigation. Giet of Police Frank Riddle said: “Whether it was intentional or not, a man is dead. “That makes it murder. Pe CARL ROSS, 63-year-old custodi an at the “Y was killed instant ly Tuesday morning by 2 power ful dynamitelike explosion in the stairwell landing by the side door. Under Indiana law, if a person is killed in the course of the commission of 2 felony, it be comes first-degree murder. In tent to kill is not a necessary ele ment to such a case. Placing or throwing a deadly explosive, Particularly in an in habited building, is a crime. Chief Riddle pointed out Lending weight to the murder theory is the fact that the alleged “killer” must have been well acquainted with Ross’ daily rou tine. DETECTIVES Ray. Tryon and Gene Butts, in charge of the in vestigation, said Ross habitually arrived for work right at 7 o'clock, went up into the lobby to turn on the light, place his lunch on the counter, opened the front door to the public, then followed a set routine. The fatal blast came shortly after 7 A. M., Ross having enter ed the rear basement door about 6:55 A. M., carrying the paper sack containing his lunch. After the blast, his lunch was on the counter as usual, showing Ross had come into the lobby during the final minutes of his c. His blasted body —the right arm blown off—was found face down just three feet from the side door of the stairwell at 7:07 A.M. Finhe BIGGEST handicap to the in vestigation, the detectives point out, if no one has come forward to say he actually saw Ross in side the building, or just what the victim was doing or carrying