Conversation so far:
Why was Erich imprisoned?
Mielke was then put on trial for ordering the shootings of East Germans who were trying to defect to the West.
was he found guilty?
In November 1994, the presiding judge closed the proceedings, ruling that Mielke was not mentally fit to stand trial.
Was he ever jailed?
At 87 years of age, Erich Mielke was Germany's oldest prison inmate and had been incarcerated for 1,904 days.
Was he released?
In 1995, parole officers and Mielke's attorneys argued that he was "totally confused" and obtained his release.
what other reason did they have for releasing him?
Public Prosecutor of Berlin announced that he was "not interested in chasing an 87 year old man anymore.

Question: could you give me more information about his imprisonment please?
Self-contained rewrite: could you give me more information about Erich Mielke's imprisonment please?