behind bars

bar（鉄棒）の後ろ（behind）とは、どういう状況でしょうか？

"bars"は複数ですから、鉄の棒は1本ではありません。そう、行く手を遮る鉄棒が何本も目の前にある状況、鉄格子です。

鉄格子に阻まれているというのは、要は拘束されている状態、牢屋に入れられているということです。

全米のみならず日本でも大ヒットした映画「パルプフィクション」の脚本家が、刑務所に逆戻り、というニュースが目を引きました。飲酒運転での過失致死の容疑で有罪になったのですが、その後、恩赦の一種でしょうか、"furlough program"の恩恵にあずかっていたところを、ツイッターでの投稿があだとなって刑務所に戻ることになってしまったそうです。


Pulp Fiction co-screenwriter Roger Avary has been sent back to a secure jail after reportedly giving updates on his sentence on Twitter.

Avary, who was jailed for a year for killing a friend while drunk driving, had been on a furlough programme, allowing him to work outside jail.

But this has now been rescinded and he has been sent back to jail.

It was revealed he was not serving jail time after a blogger asked how he could send internet updates from behind bars.

The Los Angeles Times then found out he was on the work programme and that he had not actually spent a night in a conventional jail since he was sentenced in September.

The tweets purportedly written by Avary gave the impression of a grim life on the inside, sharing a cell with a "gangbanger", and using his inmate number 34.
(Writer Roger Avary sent to secure jail after tweets. BBC News. November 30, 2009.)