"John Doe" and "Jane Roe" in Japanese

[quamp]

John Doe is the name used in English when a person's real name isn't known, or used to refer to the average man on the street. Jane Roe is the female equivalent of this.
I've been asked to help translate a murder mystery into Japanese. The victim's name isn't revealed until the middle of the story, but he gets murdered at the beginning. They refer to him as John Doe until the middle of the story. I was wondering what the Japanese equivalent to this names is, and what the female version would be

I know in Spanish they use the most common names: Juan Perez and Maria Perez. I understand Watanabe is one of the most common names in Japan. So is it something Watanabe?
:?

[nhk9]

From Wikipedia:

山田太郎 (Yamada Taro, a common male name), 山田花子 (Yamada Hanako, a common female name), 名無しの権兵衛 (Nanashi-no-Gombee, 名無しの meaning nameless, 兵衛 (hyoue) meaning member of the imperial guard and 権 (gon) being used to describe titles or positions, "Nameless member of the imperial guard". The term was transformed into nanashi-gonbee, meaning colloquial "Nameless Mr. So-and-so), 何野某 (Nanno Nanigashi), 土左衛門 (Dozaemon, a drowned corpse)

[Mike Cash]

Sometimes referred to as 仏 (hotoke)　when the name is not known. I think that is largely a police slang/jargon thing, though, and not used on documents.

(I thought females were Jane Doe. Never heard "Jane Roe" before).

EDIT:

Need to clarify that the 仏 slang is used only in the case of corpses. And sometimes used even when the name is known, I believe.

[Elizabeth]

Sometimes referred to as 仏 (hotoke)　when the name is not known. I think that is largely a police slang/jargon thing, though, and not used on documents.

(I thought females were Jane Doe. Never heard "Jane Roe" before).
"Jane Roe" was the pseudonym of the woman who helped win the right to legalized abortion in the United States. I've never heard it used to refer to an anonymous or average person outside that context.

[Mike Cash]

I feel silly now, Elizabeth. I've heard "Roe v. Wade" a zillion times in my life and never made the connection to "Roe" being a placeholder name. (Always wondered how the baby in that case felt.....he's out there somewhere, you know).

[quamp]

私はばか です. :p
I looked everywhere for this except wikipedia.

Legally speaking, Jane Roe is the correct name for a woman whose real name is not known. Although it is seen sometimes as Jane Doe, butt usually in informal situations.

(The Roe in Roe vs. Wade was really named Norma. She didn't want her real name being used due to the sensative nature of her case.)

[Tomii515]

My friend's name is Jane Ro =D

haha