Is it possible that people who go are in jail not prison can be released because the police sympathize ?

Once the person is arrested there is a protocol that must be followed. So any leniency  shown must be shown when the person first is first contacted, Much depends on the infraction of the law.

Once an arrest warrant is issued the options of the officers are eliminated. If the person has been sentenced a police officer also has no option with out facing negative consequences.

An officer can testify for the defense if they sympathize, but it is still up to the judge and the jury. Because jail terms are often too short for the inmate to have to appear before a parole board help there would be not available. If the person was in prison then an officer could appear before the parole board to give testimony.

The Police can sympathize all the care to sympathize.  Once a person is charged and jailed the Police have no say in the disposition.

Ah, no Bro. jail is short term and prison long term. If the judge decides long term you go to prison right after the sentence is handed down, give or take a few more days in jail