Cryptonym: ESMAJOR-20
However, two brothers appear to be ruled out as possibly being ESMAJOR-20. Francisco Mendez Francisco Méndez Montenegro because he apparently died in June 1957. As apparently can Mario Méndez Montenegro, who allegedly died by assassination on October 31, 1965, and was a former Guatemala City major. The other named brother, Guillermo A. Méndez Montenegro, Colonel and Doctor, allegedly died on September 12, 1970, aged 47.
As the CIA documents that mention ESMAJOR-20 are from September and October of 1968, it is possible that Guillermo A. Mendez Montenegro was E-20. However, it also possible that ESMAJOR-20 was was one of the unnamed siblings of President Julio Cesar Mendez Montenegro.
09/00/68: Cable from Guatemala City to Director (Info: Mexico City): Slugline RYBAT TYPIC LIRING: ..."2. If Mexico City has changed above position and now agrees WOFIRM (CIA) interest can be indicated, suggest following approach: Station will advise ESMAJOR-20 that Mexico City has developed an operational interest in LIRING-3's wife but unable proceed with operation because of her concern over fate of her husband. We can then ask ESMAJOR-20 attempt ascertain when trial scheduled and indication what sentence may be. Believe any interest ESMAJOR-20 may reveal to the courts will develop response. On the other hand, if there is no objection to revealing WOFIRM interest directly in LIRING-3 (Carlos Jurado-Delmar), the Station can so advise ESMAJOR-20 and request his help. 3. File: 201-248917." - - - 2022 release, page 28: https://documents3.theblackvault.com/documents/jfkfiles/jfk2022/104-10176-10004.pdf
09/24/68: Memo for the record from WH/1, Withheld: Subject: 17 September 1968 discussion with DRISCOLL re LIRING/3 (Carlos Jurado-Delmar) & LIRING/4 (Chichay Jurado): Participants: Driscoll, Kerbe, Francis and Laurence Piper (C/WH/2/G): Page 2: ..."4. In the above regard L/3 was discussed with Mr. Piper of the Guatemala desk. Mr. Piper believed the Station has a high enough contact with the Guats (ESMAJOR/20 - President's brother) to arrange to get L/3 and his Mexican compatriot out of prison and back to Mexico with a minimum security risk. Driscoll said he would initiate the cable upon his return to Mexico after he has talked with L/4. Driscoll felt he should possibly travel to Guatemala and have a preliminary meet with L/3 before Guat Station makes any all out effort to officially request L/3's release. If, after seeing L/3 Driscoll is satisfied that L/3 is still an ally and is willing to cooperate after his release then Driscoll believes we should attempt to have the Station intercede with ESMAJOR/20. Hopefully, ESMAJOR/20 will arrange the release so that all involved believe it has been done at the request and urging of the Mexican Government. Driscoll, however, would like L/3 and L/4 to believe he (Driscoll) had something to do with the release in order to raise his status with both for the sake of future operational tasks he will levy on them." - - - 2022 release, page 13: https://documents3.theblackvault.com/documents/jfkfiles/jfk2022/104-10176-10222.pdf
10/04/68: Cable from Director to Guatemala City (Info: Mexico City) (Orig: Withheld, WH/1/3E04): "1. Appreciate Ref A response. Agree we do not want surface WOFIRM (CIA) interest LIRING-3 (Carlos Jurado-Delmar) or wife to GUATs if can be avoided. 2. Ref B was sent following discussion with LIRING-3's case officer, Rowton (probably Ernest Tsikerdanos) who still TDY HQs. After further discussion with Rowton, however, we prefer GUAT station take no action on Reference B request until Rowton returns Mexico. He can then attempt obtain updated reading on LIRING-3 status from LIRING-4 (Chichay Jurado) or other source, after which Rowton and Mexico City station can decide if ESMAJOR-20 intervention warranted. 3. Index 201-248917, 201-798301." - - - 2022 release, page 10: https://documents3.theblackvault.com/documents/jfkfiles/jfk2022/104-10176-10222.pdf
https://en.wikipedia.org/wiki/Julio_C%C3%A9sar_M%C3%A9ndez_Montenegro
"Julio César Méndez Montenegro (November 23, 1915 [1] – April 30, 1996) was the Revolutionary Party President of Guatemala from July 1, 1966 to July 1, 1970. Mendez was elected on a platform promising democratic reforms and the curtailment of military power. The only civilian to occupy Guatemala's presidency during the long period of military rule between 1954 and 1986. Mendez had assumed the presidency under a pact in July, 1966 that gave the armed forces carte blanche with respect to internal security matters and an effective veto over governmental policy. [2] He was the first cousin of César Montenegro Paniagua whose kidnapping, torture and murder during the Julio César Méndez presidency is rumored to have been undertaken with presidential sanction..."
https://www.geni.com/people/Julio-M%C3%A9ndez-Montenegro-Presidente-de-Guatemala/6000000014290836006
Julio César Méndez Montenegro, Presidente de Guatemala. Birthdate: November 23, 1916. Death: April 30, 1996 (79). Immediate Family: Son of Marcial Méndez Mendoza and Mélida Montenegro Amado. Husband of Alma Sara de la Hoz de León. Father of Private; Private and Private. Brother of Private; Francisco Méndez Montenegro; Mario Méndez Montenegro; Guillermo A. Méndez Montenegro, Coronel y Doctor; Private and 1 other."
https://www.geni.com/people/Guillermo-M%C3%A9ndez-Montenegro-Coronel-y-Doctor/6000000045669524902
"Guillermo A. Méndez Montenegro, Coronel y Doctor Birthdate: April 03, 1923. Death: September 12, 1970 (47). Place of Burial: Guatemala City, Guatemala, Guatemala. Immediate Family: Son of Marcial Méndez Mendoza and Mélida Montenegro Amado. Brother of Private; Francisco Méndez Montenegro; Mario Méndez Montenegro; Julio César Méndez Montenegro, Presidente de Guatemala; Private and 1 other."
https://www.geni.com/people/Francisco-M%C3%A9ndez-Montenegro/6000000032744218992
"Francisco Méndez Montenegro: Birthdate: April 08, 1908. Birthplace: Guatemala City, Guatemala, Guatemala. Death: June 1957 (49) Guatemala City, Guatemala, Guatemala. Immediate Family: Son of Marcial Méndez Mendoza and Mélida Montenegro Amado. Brother of Private; Mario Méndez Montenegro; Julio César Méndez Montenegro, Presidente de Guatemala; Guillermo A. Méndez Montenegro, Coronel y Doctor; Private and 1 other."
https://www.geni.com/people/Mario-M%C3%A9ndez-Montenegro/6000000020240787359
"Mario Méndez Montenegro: Birthdate: November 30, 1910. Birthplace: Chiquimulilla, Santa Rosa, Guatemala. Death: October 31, 1965 (54) Guatemala City, Guatemala, Guatemala (Assassination ). Immediate Family: Son of Marcial Méndez Mendoza and Mélida Montenegro Amado. Husband of Private. Father of Private and Private. Brother of Private; Francisco Méndez Montenegro; Julio César Méndez Montenegro, Presidente de Guatemala; Guillermo A. Méndez Montenegro, Coronel y Doctor; Private and 1 other. Occupation: Guatemala's City Mayor."