Commissioners
James Lawrence Fly, Chairman
Paul A. Walker
Norman S. Case
George Henry Payne
T.A.M. Craven
Ray C. Wakefield
C.J. Durr

Address all communications to the Secretary

T.J. Slowie, Secretary

FEDERAL COMMUNICATIONS COMMISSION
Washington 25, D.C.

April 4, 1944

Honorable Francis Biddle
Attorney General
Washington, D.C.

My dear Mr. Attorney General

This is in reply to your letter of February 26, 1944 with reference to Lieutenant General John L. DeWitt's Final Report on Japanese Evacuation from the West Coast, which was recently made public to by the War Department.

You state that you are interested in the accuracy of General DeWitt's account, in the first two chapters of the Report, of the events leading to his decision that military necessity required the evacuation, and you note that prevention of signaling by persons, presumably of Japanese descent, on shore to enemy surface vessels or submarines off the coast apparently was a very considerable part of the problem with which General DeWitt was concerned during the period between December 1941 and July 1, 1942, when the evacuation was substantially complete. You direct attention praticularly [particularly] to his reference to hundreds of reports of such signaling by means of signal lights and unlawful radio transmitters and state that investigation by the Department of Justice of great numbers of rumors concerning signal lights and radio transmitters proved them, without exception, to be baseless.

You inquire, first, whether during the period from December 1941 to July 1, 1942, the Commission was engaged on the West Coast in monitoring and identifying signals reported to be from unlawful transmitters and in locating any such transmitters; and, if so, the number of reports received by the Commission during this period of unlawful or unidentified signals, with a detailed break-down of the results of its investigations:

Throughout this period on the West Coast as elsewhere throughout the United States and its territories, the Commission's Radio Intelligence Division was engaged in a comprehensive 24-hour surveillance of the entire radio spectrum to guard against any unlawful radio activity.

Within the area on the West Coast from which the Japanese were subsequently evacuated, the Commission's Radio Intelligence Division had in operation two Primary Monitoring Stations, located at Portland, Oregon, and San Pedro, California, and nine Secondary Monitoring Stations, located at

Seattle, Washington; Portland, Oregon; Arcata, California; Larkspur, California; Fresno, California; Los Angeles, California; San Diego, California; Yuma, Arizona, and Tucson, Arizona. During the period here involved, the Secondary Station at Larkspur, California, was moved to San Leandro, California, and was expanded to a Primary Monitoring Station; and the Secondary Station at Yuma, Arizona, was moved to Salinas, California. The Commission had additional stations at other places within the Western Defense Command.

At all stations, there were special receivers and recorders for intercepting and recording signals throughout the entire radio spectrum. The Primary Monitoring Stations were equipped with extensive antenna arrays and Adcock high-frequency direction-finding apparatus for taking bearings upon sky-wave signals received from all over the world. They were tied in with other Primary Monitoring Stations on the continent as well as in Alaska, Hawaii and Puerto Rico, which together constituted a nation-side direction-finding system for immediate coordinated action in taking bearings upon and establishing the fix of any suspected transmitter and for exchanging other information relative to identity of radio stations. At the Secondary Monitoring Stations were mobile units, equipped with loop direction finders, by taking bearings within its ground-wave range. Other devices enabled investigators to determine the exact house or even room in which a transmitter was located.

Soon after December 7, 1941, at the request of General DeWitt, the monitoring facilities described above were supplemented by patrols of mobile direction-finding intercept units along the West Coast from Canada to Mexico. These patrols were instituted for the particular purpose of detecting any radio transmissions from shore to ships off the coast.

In the early months of the war, the Commission's field offices and stations on the West Coast were deluged with calls, particularly from the Army and Navy, reporting suspicious radio signaling and requesting the identification of radio signals. In hundreds upon hundreds of cases, identification of the signal was made by Radio Intelligence Division personnel merely by listening to it right at the monitoring station. In no case was the transmission other than legitimate.

In the case of 760 reports of unidentified or unlawful radio signals within the evacuated area during the period in question, which could not be heard or identified by listening at the monitoring station, a field investigation was conducted by mobile direction-finding units. In 641 of the cases it was found that no radio signaling at all was involved. Of the 119 cases remaining, 116 were found to involve lawful transmissions by following stations:

United States Army Stations - 21
United States Navy Stations - 8
Local Police Stations - 12
United States and Foreign Commercial Licensed Stations - 65
Japanese Stations in Japanese Territory - 10
----

116

The final 3 were found to involve the very short-range transmissions of the ordinary commercial type phonograph oscillator used in playing recordings for home amusement.

There were no radio signals reported to the Commission which could not be identified, or which were unlawful. Like the Department of Justice, the Commission knows of no evidence of any illicit radio signaling in this area during the period in question.

You also ask the extent to which General DeWitt or his subordinates were informed of the operations of the Commission's Radio Intelligence Division. The General and his staff were kept continuously informed of the Commission's work, both through occasional conferences and day-to-day liaison. In the earlier part of the war, there was constant contact by telephone between Radio Intelligence Division stations and Army and Navy posts along the West Coast for the purpose of furnishing these agencies with bearings and other information pertaining to radio signals. And as the result of a request of General DeWitt in January 1942, the Commission established a Radio Intelligence Center in San Francisco for coordinating radio intelligence information collected by the Army, Navy and the Commission. This Center was tied in by teletypewriter circuit with the Primary Monitoring Stations on the West Coast, as well as with other Primary stations on the Continent through headquarters in Washington. As a result, it was an integral part of the Commission's nation-wide direction-finding system described above. As a part of the plan for coordinating activities, Army and Navy personnel maintained a liaison attendance at this Center. Both these services, moreover, had a direct telephone circuit from the Center to their headquarters.

You direct attention, further, to the statement in General DeWitt's Report that following the evacuation, interception of suspicious or unidentified radio signals and shore-to-ship signal lights was virtually eliminated. You state it was the experience of the Department of Justice that, although no unlawful radio signaling or any unlawful shore-to-ship signaling with lights was discovered, a great number of reports of such activity were received, and that these did not diminish in number following the evacuation. It is likewise the Commission's experience that reports of unlawful radio signaling along the West Coast -- which in each case were unfounded -- were not affected by the evacuation. In fact, throughout the year 1942, the number of reports of unlawful radio operation requiring investigation by mobile units which were received in the States along the West Coast varied in close parallel with the number of such reports received throughout the whole country.

Finally, you refer to General DeWitt's memorandum of January 5, 1942 to James H. Rowe, Jr., Assistant to the Attorney General, set out in the Report, in which concern is expressed over the action to be taken in a case where there should be strong evidence of shore-to-submarine radio communication, but the unlawful radio transmitter could not be located within an area more precise than a city block, or even a general area such as Monterey County.

You note that the memorandum suggested that available means were inadequate to locate and seize any such radio transmitter, but state that if your understanding that equipment was available for locating such a transmitter is correct, the problem with which General DeWitt was concerned would not arise in practice. Your understanding is correct. As noted above, equipment developed by the Commission's engineers was on and after December 7, 1941 in the hands of its personnel on the West Coast, which enabled them easily to locate the individual house and even the exact room containing the concealed transmitter.

Pursuant to your request for any other information we may have bearing on the accuracy of the statements in the Report indicating the existence of illicit radio signaling along the West Coast, additional facts are set forth in the enclosed memorandum.

Sincerely,

/s/ James Lawrence Fly
Chairman