YOUNGSTOWN, Ohio - Three months after a Youngstown firefighter was shot on the job, police tell 21 News that they were just recently told there was no DNA found on the shell casings.

No one has ever been charged with the shooting and investigators had been waiting to see if a person of interest would be linked to the crime through DNA.

Youngstown police sent shell casings to Ohio BCI to be tested for DNA evidence and none was found, according to Lieutenant Doug Bobovnyik. 

Police said that despite this development, the case still remains under investigation.

The firefighter who was shot back in December while on a call was back on the job Monday.

Youngstown's Fire Chief John O'Neill, Jr. tells us it will be the first day back for Lt. Paul Lutton, who was driving a fire engine when a gunman opened fire on the city's North Side in December.

A bullet struck Lutton's right leg, embedding shrapnel in his calf.

One of the other three shots fired grazed the coat of firefighter Dwayne Montogmery.

Police were investigating the possibility that Cameron Dyer of Youngstown was the person who fired the shots at the truck on Halleck Street.

Dyer is scheduled to go on trial next week on a charge of disrupting public services for allegedly arguing with firefighters while they were battling that blaze.

Investigators had been conducting ballistics tests and awaiting DNA results to determine whether or not Dyer is linked to the shooting.

Dyer is currently serving a 30-month prison sentence for cocaine possession.