(WSBT) The family of the gunman who shot and killed a South Bend police officer says he was mentally ill.

Scott Barnaby shot and killed Corporal Nick Polizzotto and injured Patrolman Michael Norby at the Wooden Indian Motel in South Bend.

Barnaby was also killed by return fire.

The loss of one of their own is still evident outside the South Bend Police Department. Polizzotto’s squad car remains overcome with tributes and flowers.

This week the Barnaby Family sent a letter to the police department.

“It's certainly a departure from what we're used to. Typically when something happens and the police department or a member of the department is a victim, it's uncharacteristic to hear from the family or the suspect,” said South Bend Captain Phil Trent.

In the letter, Barnaby’s family offered their condolences to Polizzotto's family and the police officers.

They say Barnaby had been a drug addict and mentally ill for many years.

Due to those issues, the letter says they had anticipated an early death but not the loss of an innocent life.

Barnaby's family members tell WSBT that Barnaby abused drugs and was diagnosed with paranoid schizophrenia years ago and had stopped taking his medication.

It brings back a number of questions as to why Barnaby had the gun in the first place.

Licensed gun dealer Ronald Wedge of Bristol faces charges for selling Barnaby the gun without doing a background check at the time and keeping false records.

Barnaby eventually cleared the background check, but it was after he had shot the officers.

According to a spokesperson with the Bureau of Alcohol, Tobacco, and Firearms, if a judge had ruled Barnaby mentally incompetent, he says Barnaby would never have passed the background check.

Also, there is a federal form that must be filled out to purchase a gun. Wedge filled one out when he made the sale to Barnaby.

It specifically asks about drug use and mental illness.

If you lie on the form, it's a felony.

“There were some mistakes and some outright illegalities that occurred. Those things combined to end in tragedy,” commented Trent.

Barnaby's family tells WSBT, they hope to get more information on mental health issues and gun laws to the public through this tragedy, so it doesn't happen again.

The last day for Corporal Polizzotto's memorial outside the South Bend Police Department will be Sunday.