約瑟夫·季南性格外向，好交友。表面上往往談笑風(fēng)生，周旋自如，慷慨大方，但實(shí)際上知道何時(shí)避重就輕，必要時(shí)可以玩弄一些“詭計(jì)”，有些政客作風(fēng)。

1945年12月16日，蘇、美、英在莫斯科舉行會(huì)議，決定組成由美國(guó)、中國(guó)、英國(guó)、蘇聯(lián)、法國(guó)、澳大利亞、加拿大、新西蘭、荷蘭、印度和菲律賓十一個(gè)國(guó)家參加的遠(yuǎn)東國(guó)際軍事法庭。根據(jù)《遠(yuǎn)東國(guó)際軍事法庭憲章》，法庭有權(quán)審判犯有以下三種罪行的日本甲級(jí)戰(zhàn)犯：破壞和平罪；戰(zhàn)爭(zhēng)罪；違反人道罪。約瑟夫·季南被任命為遠(yuǎn)東國(guó)際軍事法庭首席檢察官兼盟軍總部國(guó)際檢察局局長(zhǎng)。

東京審判開(kāi)審前，初到東京，季南就公開(kāi)表示，要運(yùn)用在司法部工作的經(jīng)驗(yàn)，和日本戰(zhàn)犯對(duì)質(zhì)公堂，制服這幫強(qiáng)盜。在法庭上，季南能言善辯，提問(wèn)尖銳，經(jīng)驗(yàn)老到。有時(shí)喜好長(zhǎng)篇發(fā)言，用大文章，引用“名人名言”（如羅斯福等），因傲氣自負(fù)，脾氣有時(shí)不免暴躁。由于他的強(qiáng)悍、雷厲風(fēng)行和高壓態(tài)度，人們送給他一個(gè)綽號(hào)“魔鬼檢察官”。

在季南的強(qiáng)勢(shì)推動(dòng)下，國(guó)際檢察局全力以赴地投入到審訊戰(zhàn)犯、搜集證據(jù)的工作中。檢察官們作了分工，分擔(dān)了日本的戰(zhàn)爭(zhēng)準(zhǔn)備、中國(guó)滿洲事變、日本全面侵華和發(fā)動(dòng)太平洋戰(zhàn)爭(zhēng)等各階段的起訴工作。

1946年4月29日，季南正式向法庭遞交起訴書。一天后，起訴書被送到28名被告手中。

1946年5月3日上午8點(diǎn)42分，押送日本戰(zhàn)犯的車來(lái)到遠(yuǎn)東國(guó)際軍事法庭門口。在《朝日新聞》記者眼里，“這群戰(zhàn)犯就像一支匆匆送葬的隊(duì)伍”。

遠(yuǎn)東國(guó)際軍事法庭庭長(zhǎng)衛(wèi)勃爵士讀完開(kāi)庭詞，首席檢察官季南開(kāi)始宣讀起訴書。一個(gè)日本記者對(duì)開(kāi)庭第一天曾作過(guò)比喻：“每一幕都恰似觀看莎士比亞的名劇！”

（英漢對(duì)照）

Ladies and Gentlemen,honorable judges and members of the court.

All of the accused joined in a formulation and execution of a plan, a conspiracy whose purpose was to establish Japan's military, political and economic control over the countries within the Pacific and Indian Oceans. In order to achieve this goal, Japan alone or working with other countries of like mind, embarked on a war of aggression, to subjugate all who stood in their way.

My prosecution team and I have produced more than enough evidence to prove the participation of the accused in these criminal actions.Throughout the history of civilization, no one has ever seen human nature at such a peak of cruelty and barbarity. Countless people have died horrendous, unthinkable deaths to feed Japan's insatiable appetite for expansion. By their actions, they have challenged human civilization, they have challenged peace and they have challenged the whole world. Their common objective, a criminal objective, was to ensure the domination of Japan's Empire.

There is no greater crime than plotting and executing a war of aggression. The security of the world and its people was threatened by this plot and destroyed by this war, the only possible outcome of which is the great suffering the world has faced.

Therefore, I, Joseph Keenan, on behalf of my colleagues in the ally prosecution team, solemnly request the honorable judges of the International Military Tribunal for the Far-east to severely punish those responsible for this horrible war of aggression in the name of justice, in the spirit of compassion and in the name of humanity!!!

“女士們，先生們；尊敬的庭上；尊敬的各同盟國(guó)法官們：全體被告參與了這一共同計(jì)劃的擬定或執(zhí)行，這一共同計(jì)劃的目的，是為了日本取得對(duì)太平洋及印度洋地區(qū)國(guó)家的政治、軍事、經(jīng)濟(jì)的控制地位！為了達(dá)到這個(gè)目的，日本單獨(dú)或與其它具有同樣目的的國(guó)家發(fā)動(dòng)侵略戰(zhàn)爭(zhēng)，以對(duì)付反對(duì)此侵略目的的國(guó)家！我以及我們檢查團(tuán)的全體同仁，用我們的努力和證據(jù)，證明了上述目的的陰謀及罪行都確有其事！

縱觀人類文明史，其手段之殘忍、殘酷、滅絕人性實(shí)屬罕見(jiàn)！無(wú)數(shù)的生命痛苦地消失在日本侵略野心的槍口和刀口之下！他們的這種行為是對(duì)人類文明的挑戰(zhàn)！是對(duì)和平的挑戰(zhàn)！是對(duì)世界的挑戰(zhàn)！他們共同的犯罪目的是為了確保天皇的統(tǒng)治地位！

沒(méi)有比發(fā)動(dòng)和實(shí)行侵略戰(zhàn)爭(zhēng)更加嚴(yán)重的罪行！全世界人民的安全，被這種陰謀所威脅！被這場(chǎng)戰(zhàn)爭(zhēng)所破壞！這個(gè)陰謀的唯一結(jié)果，就是使全世界遭受死亡和痛苦！

所以，我——約瑟夫·季南——代表盟國(guó)檢查團(tuán)全體同仁鄭重向遠(yuǎn)東國(guó)際軍事法庭庭長(zhǎng)及各位法官提請(qǐng)，請(qǐng)你們給這些發(fā)動(dòng)和實(shí)施侵略戰(zhàn)爭(zhēng)的被告?zhèn)円試?yán)懲！請(qǐng)你們以公正之心，以善良之名，以人類之愿！”