A mistrial has been declared Monday in the case of a 21-year-old New York City man accused of killing a Syracuse University graduate student from Bulgaria, the Associated Press reported.

On January 20 Simeon Popov, a 27-year-old Bulgarian, living in the town of Syracuse, NY, in the United States was shot to death by an armed gunman.

He was pronounced dead at the Syracuse University Hospital from a gunshot wound to the head.

Popov worked in a pizza restaurant and on his way to deliver a pizza he turned out to be at a place where a robbery was being committed. Popov was a graduate student in the Setnor School of Music in Syracuse University's College of Visual and Performing Arts. He was accepted to the Syracuse University in 2000 to pursue master's degree in music. His specialty was trombone.

Dominic Dennard Jr. of the Bronx, who faced charges of first- and second-degree murder, first-degree robbery, first-degree burglary and second-degree criminal possession of a weapon, will be tried again.

Prosecutors said there was enough evidence in the case, but there was no DNA evidence to link Dennard directly to the crime.

They think the retrial cannot be expected to begin for several months.

"To have to put them through this again is heart-wrenching," the Associated Press cited Assistant District Attorney Nicholas DeMartino as saying about Popv's parents who observed the trial.