Under glass
From Fresh Dictionary
English
Idiom
under glass
- ((slang{{#if:|, {{{2}}}{{#if:|, {{{3}}}{{#if:|, {{{4}}}{{#if:|, {{{5}}}{{#if:|, {{{6}}}{{#if:|, {{{7}}}{{#if:|, {{{8}}}{{#if:|, {{{9}}}}}}}}}}}}}}}}}}})): To be in jail, or under close inspection (i.e. under a microscope).