POSTED AND FIVE NEED IN KILLINGSCounty Offers $500 and Transit Firm $1,000 inCar Barn Murders.FOUR MEN AND WOMANQUESTIONED IN CASEFootprints. Bullets and GunShells Only Clues Found to Hold-up Slayers.Reward totals were raised to $1,500for information leading to the arrest and conviction of the persons guilty of the brutal killing early yesterday of two Capital Transit Co. employes and robbery in the car barn office at Chevy Chase. Md. a few miles north ol the District line.At the same time police revealed they had four men and a woman under arrest in connection with the crime.The Montgomery County Commissioners. meeting today, offered $500 reward, while the Capital Transit Co. yesterday offered a reward of $1,000.Meanwhile investigators were hoping that the feu meager clues they have may aid in a solution. These include bullet*, recovered from woodwork in the office and from the heads of the two dead men—James M. Mitchell. 59. 2216 Thirtieth street southeast, depot clerk, and Emory Smith. 40. of Bethesda. Md.. barn mechanic and watchman, who was kidnaped from the scene and thrown in Rock Creek. Also, police have several empty shells, ejected from the robbers' pistols when fired in the station, and measurements of footprints which led from an automobile which had been parked in the snow near the scene of the robbery.Former Employe Held.One of the men under arrest is a former employe ol the street car company, who. it was learned today previously was arrested for questioning in connection with a Washington hold-up. At that time Mitchell is said to have aided in the arrest through identifying the man to District detectives. The man gave himself up at police headquarters when he learned he was wanted.Another of the men arrested is astreet car operative, said to be a close friend of the former employe The woman is alleged to have been with the former employe on the night of the robbery and is understood to beunder questioning as to the man'sv hereabouts at the time of the murder and robbery.All except the street car operative, who was errer-tcd in Maryland and detained at the Bethesda sub station, arc being questioned in the District by officers from Washington. Baltimore and Montgomery County.Prints Measured.The footprints in the snow, leading from the automobile, which tracks showed had been parked nearby, were measured by police and reported to have been marie by a man wearing about a size seven shoe. The prints leading from where the automobile stood to the office were made by a man walking, it was said, while those going back toward the automobilewere made by a man who was running. There also were marks in the snow near the car. made, apparently, by a man who had fallen. Police ; were uncertain, however, whether tome one went down in a fight.Footprints at the bridge over Rock Creek where Smith was thrown in were obliterated by a throng of persons who flocked to the scene before police were able to obtain measurements. From the marks in the snow it was indicated Smith had been pulled to the creek by two men who preceded himThe 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 tragedy. These include Detective Sergt. Frank O. Brass of Washington. SergLs. T. F. Vollten and Leroy Rogers of the Montgomery Police, and Detective Sergt. S. W. Deal of Baltimore.Capital Transit officials today said the dependents of Mitchell and Smith will get $7,500. to be paid out in monthly installments under the provisions of the District workmen’s compensation law. In addition, the families 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 teen shot four times in the head.There were no bullet wounds about their bodies as had been indicated by earlier reports. Throe 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 from deep in the head and the other was lodged just under the skin after having gone through the skull.Smith, the physicians reported, had powder burns where the bullets had entered, showing definitely he was shot at close range. This gave | strength to the police theory that the robbers probably had decided to shoot him when he began to put upa fight after being kidnaped from thescene. Broken glass along the roadside at the bridge over Rock Creek, approximately a mile north on Connecticut avenue from the robbery scene where Smith was thrown into the water, furnished mute evidence of a struggle.Police thought it possible that Smith might have put up a fight at that point upon regaining consciousness after having been hit over the head. The body had drifted approximately 100 yards downstream, in the creek, swollen by recent rain and enow, from the point where it was thrown in.Mitchell had no powder marks on him. indicating he had been shot from a greater distance than Smith.Mitchell's loaded gun had neverbeen removed from the desk drawer in the car bam office, indicating he probably had been taken by surprise. Blood on a record sheet on his deskindicated he may have been shotwhile seated in a chair and turned around by the force of the bullets. He was found lying on the floor nearthe desk.