Translation:The old policeman is not going to the hospital.
Why does this not translate to "the old police office is not LEAVING [or GOING AWAY from] the hospital"? I thought "el" from away from. This sentence doesn't make sense to me at all. Does it mean that they are leaving from where they are to go into the hospital? As such, "megy el" or "elmegy" just means "goes" and doesn't necessarily mean "goes away from"?
Does the use of the co-verb "el" here preclude translating the sentence as "The old policeman is not going into the hospital?" in spite of the illative case marking? I am imagining a longer journey implied by "elmenni" over "menni" alone here? If you wanted to convey the "The old policeman is not going into the hospital" (i.e. entering) would you write "Az idős rendőr nem megy be a korházba"?
But those don't mean the same thing.
"police" is "the official organization that makes people obey the law and that protects people and places against crime, or the people who work for this organization"
(Source: https://dictionary.cambridge.org/us/dictionary/learner-english/police_1 ; emphasis is mine)
It's an organisation, or all of the people (together) who work for that organisation -- not one person. "police" in Hungarian is rendőrség.
One single rendőr is a "policeman" or "police officer".