Thr metal jacket bullets used by the robbers were fired from automatic pistols, according to Lieut. John H. Fowler, ballistics expert of the Washington Police Department.Conference Planned.The Washington. Baltimore and Montgomery County police working on the case were planning to hold a conference today at the scene of the 1 tragedy. These include Detective ) Sergt. Frank O. Brass of Washington. ! Sergts. T. F. Vollten and Leroy Rogers 1 c f the Montgomery Police, and Detective Sergt. S. W. Deal of Baltimore.Capital Transit officials today said the dependents of Mitchell and Smithwill get $7,500. to be paid out in monthly installments under the provisions of the District workmen's compensation law. In addition, the fam- ; ilics will each receive $500 in cash from the Capital Transit Relief Association and another $500 each from group insurance carried for employes ’ by the company.Both Shot Four Times.An autopsy performed in Rockville ,late yesterday by Drs. C. E. Hawks [ and William A. Linthicum revealed | that both Mitchell and Smith liad been shot four times in the head. !There were no bullet wounds about | their bodies as had been indicated by earlier reports. Three bullets wererecovered from the bodies.A single bullet recovered from Mitchell was one which had entered his cheek, taken a downward course ! and lodged in his mouth. Of two ' bullets taken from Smith, one was I from deep in the head and the other I was lodged just under the skin after ! having gone through the skull.