I think "imprisoned" is a better choice. In the United States, there are various technical legal distinctions between "a jail," "a prison," and "a penitentiary." I'm not a lawyer and don't know what they are, and even if I did they would be different in all fifty states. But I think a "jail" means a TEMPORARY detention facility where someone who has been arrested is held while waiting for a trial. He is not a criminal yet, and in theory he is not being punished. But he might be a criminal, and a judge has decided that he needs to be detained to prevent him from running away before he can be tried. That's the rough idea, anyway. Since the U.S. Constitution guarantees the right to a "speedy" trial, nobody should be "jailed for life." He should be "jailed" for at most a matter of months, then tried in a court, and, IF convicted, possibly "imprisoned for life." However, loosely speaking "jail" and "prison" are synonyms.

I read Dan's answer and it was interesting for me. I was not aware that "jail" technically refers to a temporary prison. In England and Wales, both words are used in the same way in everyday language. "Jail" is a more informal word than "imprison" but both can be seen in news articles. If a person is kept in prison while awaiting trial, we say they have been "remanded in custody". This is an expression in English law which may not be used elsewhere. We only have one type of prison though with different grades, depending on the security level.

Usage of the the words "jail"/"jailed" and "prison"/"imprisoned" may vary from place to place. However, in general: In the US, a "jail" serves two purposes. First, those accused of crime (but not yet convicted) and who are not granted bail [1] or released on their own recognizance, [2] are detained in jail while they await trial. Second, a person who is convicted of a "lesser" crime (often called a misdemeanor) will typically serve his sentence in a jail, almost always when the period of the sentence is less than one year. A person who is being held in a jail has been "jailed." A prison is a facility that houses criminals after their conviction for a more serious type of crime (usually called a "felony".) Their sentence is usually for one year or more. Such people are "imprisoned" or "incarcerated". Someone could be "imprisoned for life." [1] "bail" - money or a bond given to a court so that it will release you before trial. The money or bond will be forfeited if you fail to appear in court. If you do appear, the money will be returned to you, or the bond cancelled. [2] "on (one's) own recognizance" -- where a person is release from jail without "making bail". That is, the person is released on his written promise to appear in court. Release on one's own recognizance is used when the crime is rather minor, and the defendant has strong ties to the community, so it is likely he will not flee.