NORTHAMPTON — A trial may begin as early as October for the man accused of supplying the heroin that killed a University of Massachusetts Amherst student after he overdosed in October 2013.

Jesse Carrillo, 27, of Derry, New Hampshire, who remains free after posting $25,000 bail, has pleaded not guilty in Hampshire Superior Court to involuntary manslaughter and distributing heroin.

Carrillo is a former UMass graduate student, but was expelled in fall 2014, about a year after he allegedly sold heroin to Eric L. Sinacori, 20, who died of an overdose Oct. 4, 2013, according to the Northwestern district attorney’s office.

Carrillo’s final pre-trial hearing is scheduled for 2 p.m. Sept. 23, according to court records.

First Assistant Northwestern District Attorney Steven E. Gagne is prosecuting the case, and Carrillo is represented by prominent defense attorney J.W. Carney Jr. of Boston.

Carney previously represented South Boston gangster James “Whitey” Bulger and, most recently, a former student at St. Paul’s School in Concord, New Hampshire, in a rape trial that received national attention.

Prosecutors allege Carrillo sold heroin to Sinacori, whose father and stepmother discovered his body at his off-campus apartment in Puffton Village.

Sinacori, of Whitehouse Station, New Jersey, was a third-year kinesiology student. Ten months before his death, he had become a confidential informant for UMass Police.

Michael Majchrowicz can be reached at mmajchrowicz@gazettenet.com.