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ashinçton 25, P. d.

nclosed for your files is the original copy of cur latest tatus feport on the use of the :ico-tone dhlay instruont as an intorrogation dovice. Also enclosed for your use is a duplicate vitich you requasted in your letter to us dated Fobruary 20, 1953.

Very Tuly 7ur",

May 1h,1953

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STATUS EPORT

Rosearch en an Interrogation Cevice and Frocedure

May 13, 1953

The prinry ain md purpose of this orojoct is to ohtain a success ful interrogition device from the effects of side-tone delay, together with an aopropriate procedure for its use vith a mninimun nunber of attachments.

Tho secondary aim, being developed in this laboratory, is to obtain moro easily interprated polygraph rucords bv use of sido-tone delay in conjunction ith the polygraph.

deliverod to this labaratory a more

refined side-tone delay (STD) inatrument on March 5, l953. The construction of this now instrunent vas raquestod by the investigators ith the bolief that its rafinements would eliminate some of the difficultios cncountered in previous instruments. Tho refinements consistod of a varluble tape soaed vuích vas incorporatod with the erase, record, and plynack nead assumbly of the standard Magneeord. ln order to accorplish this; a standard Nugnecord recordtng; unit was corplctoly disnantled and then rebuilt vith a variable tino spoed. Also the standard Hrgnecord synchronous nolor was adjusted so as to drive a disc at variable distances fromthe axis. The newly constructed drive wis free from wow and had a l-l0 speed range which meant the tape apeed was 3" to 30\* per second. Tnis provided an easily adjustable variable in the

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cide-tone delay fros 0.Ohl6 to 0.hl6 seconds. Tha stndard Magnocord endlessloop tape device was utilised in plice of the standrd two-rcol device.

In February, l953 the investigators decided thit possibly batter results could be obtained if the subject was not raquired to wear earphones. On "ay 12, 1953 additional a paratus vas added to the viriable-delay equipront so thit it would be unnecessary for the subject to ear earphones. The elimination of the subject's earphones was accomplished by adding two throat microphones, an auxiliary amplifior, and two external speakers.

The microphones are of the cryatal-ccntact type and were adwtod às throat alerophcnes since no cogrercial throat micropaones uere avatlible. The subjeet's miorophone is connected to the standard Hagnecord amplifier, and the aplifior's neter switch is the STD off-and-on switch. The Hagnecord's monitoring jack is the outlet fron tuis inatrument and it is connected to the auxiliary amplifier by a sound cable. The subject'n sueech goos through this auxiliary amplifier to the tvo external speakers. The second throit microphone is ued by. the interrogator, out this nicropnone i. cennected directly to the mxiliary aaollfier, heneo t. tho two exteraal qpe hers.

Tnus, the sublect's meech can e delayed any iwo, hile tho intorrorator's sreech can never be delarod. Since tho two voices at. hoard thurough the two external speakera, tho subject will be less likely to su pect that his voice is being delayed because bothi voices will sound alike, even though the intarrogntor's voice is not delayed.

02#

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β Threngh expariaentation at Ue lalortory it sag fount that two extornal upeakers wero much more effeative in inducing Uhe STp effect than ono speaker. With only one spenker the subject can tum his hoad and focus his attention awar fron the source of his delayed zpeech. Tho best romatlts Pere cbtained riun the two epeakors vere placed on eitber side of tho subjoct.

The variable-dolay instrument delivered in Mirch proved to be the most durable so far tested bacause of its Lmproved design and batter construction. It movided the interrogator ith an instrument shich did not hive disturhing vow, fluttor, or noises. The imaigitors thought that this irproved instrumsnt would provide a better evaluation of the variable delay becalse of there refinenents. It was believed that more subjects wouid be affected by the side-tone delay phenomenon viththis iproved inatrument. Hovever, in actual criminel cases it. tan found that the suojects ho vere not affected by a prodeterrined 0.20 seconds delay tero usually nct affocted chen by. vuriablendelay deviea vas used. Tais was true even though the ontire ruge fron O.ohl6 to 0.hl6 soconds was utilized.urthormore, the sabjects ho vare affectod t uny extent by th: predotoriinad delay of 0.20 -ceonds ern alsem ffnctod to ry grontor extent ahon the delay waa increased or decreased. Thes raguilts again indicated to the invugtigators that possibly the aubject's amount of education, intelligence or social conscicumness was relatod to the amount of difficulty he e xoerlenced in speaking when the STD instrument aus operating.

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It wus oricinally thonght that the nore diffieulty a cuilty suhjoct had in cpeaking because of the Ftn effect, the more likoly hu vis to confess Hovever, it was discovored that many guilty subjects confessed even though thair speech was unaffeoted by the STD davice.

Therefore, slnce dau ry she invustir ttors ere nos too concernod ahout, tho efioct of the sirie-tone delny ner se, bst they concentrated on the prccodures to be uaed sith the TD instrument so that confessions could be more casily and readily obtained. The results then obtained kith the variablee delay instrumnt bore out this belief as well. as the soundnoss of the nlan af bine nore concarnad uith interrogationa. techniues ane oroceduros rather than vith the Stn offoct.

It was found that approximately the sae percentage of guilty subjects confessed when the variablo-delay instrurent was used fcr the interrogation as when the one fixed delay instrunent vas used. vrom the incptien of thls contract to May ll, 1953 this percentage of confessions frox interrogated mullty subjeots amnunted to mproxiaitely 56 cr: nont. Thls figure of 56 por cont can he contrasted to the percentage of crininal confessions giimd at thelaboratory betaeen January 1, lohe and Pecembor 3l, 1952. Auring this flvc-yenr period, hen no sicestono delny instruonts were used on these anbjects, proximately 62 ner cent of the Interrogated subjects did confana to the crime under investigation.

Thus when one reviews the past year in ita entirely, it appears that the side-tone delay tid not increase the percentage of confessions.hen a confession was zained by the use of tho Tp instrument, It did not zuaterilly

ahs

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recuce the tire ropired for obtaining tha oonfession, nor did it gake tho interrogation any easier. urthermere, the investiglcors suiieve thint tho great majority of those who did confess would have confessed withcut the uoa of the STD instrumsnt.

Ln faet, there is a ceod po sibility thtt tho aeo ef the GTD actually

shocpad a nur er ef subjeets fron confessing their crimes. Thia vas definitely

proven to be true in two cases when, after fulis confessing, the aubjects

stuted that they Hd not confess earlier bocause of the MD and that trey

waitod wntil the .T instrurcnt vag turnod off before dolie ao. also, it ia

trljved that. durin; ay ther interrogttions the tuiity cuojtcts were so

confused nuni bewilcorul oy the TD effect that they were no longer cncorned

about their crime and were not listening to shat tho interrogator said. hon

the subject is actually cietracted by he effects of the Tb, tha interregator'a

persuaslveness is lost smi there is little likelihood of ohtaining a confossion.

It isthe opinion of the investigators that the future holds vury ilttle

kops for Lhe lde-tore doley inntruont at an eficetive interrog atiou dovice.

lou ocbansively terted in this iaboratory was the hypothesis that the

ure of to Tr vould ptedacs noe aily in' :rpreted oelyeranh racards, the

inv etiztors consieral tlis ss importan tint tusy alded it to the projeot

is ita meondary ain. Vari us !ypes of answurs (jos or no, snort-term, iong-

term, and narrative tyoe answers) vere experimented with during polygraph teste

whan the TD instrumont was also being operated.

#5

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in the rajerity of ins.ancea the Th was inofiective in producing the dosirud rusults, and in aany instancos tha r affected polytraph records so that they were more difficult to interpret. In fact, on two occasions the use of the Sül) actaally defeatad the purpoce of the poly,ranh tests. en thcso weasions the stec-beno dela, caused tao vuriiied innucent surjeets to ruspond as if Uhey were aotuatly guiity.

For these reaaone the investigators beliove that the STD instrumont should not be uged in conjunction with the polygraph test.