Madison police served an arrest warrant Thursday after an investigation into heroin dealing.

Police arrested Adam M. Denning, 31, on a charge of dealing a narcotic drug, a Class B felony.

According to the probable cause affidavit from the case, Denning sold heroin to a police informant in November 2012. Records show Denning sold one gram of heroin for $70.

Denning currently has a pending case for dealing a controlled substance. Police arrested Denning after purchasing pills from him.