It is alleged that following an arrest of a NYSP officer by NYPD officers for being drunk on the job the officers of the NYPD precinct involved started getting threatening phonecalls from NYSP officers. Don't have any idea if this is true - but I can see it being true.
This needs to be thoroughly investigated. I doubt it will be, though.
Details here:
Tensions rise from threats of retaliation after NYPD arrest NYSP Trooper