Trump believes has has exclusive control over the DOJ, so maybe he should tell Sessions to back down on civil asset forfeiture

According to Sessions,

“Civil asset forfeiture is a key tool that helps law enforcement defund organized crime, take back ill-gotten gains, and prevent new crimes from being committed. It weakens the criminals and the cartels. Civil asset forfeiture takes the material support of the criminals and makes it the material support of law enforcement. In departments across this country, funds that were once used to take lives are now being used to save lives. And there is nothing wrong with adoptive forfeitures. There can be no federal adoption if the forfeiture is not called for under federal law. In many cases, adoptive forfeitures represent great partnerships between federal and state law enforcement.”
http://www.kusi.com/attorney-general-sessions-delivers-remarks-national-sheriffs-association/

Hmm...Let's see, he's the Chief Executive. The DoJ is an executive department. I'd say he's in charge just like every other President.