(WSBT) The family of the man who shot and killed a South Bend police officer says he never should have been able to buy the gun he used. They're pleading for a solution that would keep guns out of the hands of the mentally ill.

45-year old Scott Barnaby shot Patrolman Michael Norby and killed Corporal Nick Polizzotto on April 24th at the Wooden Indian Motel. Barnaby was also killed in the shoot out.

Chris Barnaby says his brother had been mentally ill since he was a teenager, but he wasn't diagnosed with paranoid schizophrenia until his early thirties. Even so, his brother says that should have been enough to keep him from getting a gun.

"I was the only one who could really talk to him," Barnaby said in an exclusive interview with WSBT. "I hadn't seen him for 2-3 years, and I tried to make contact with him on the Tuesday before Easter. It didn't go well. He didn't want to see me or be in contact with us or the family. And that was pretty much the last time I saw him."

And like many of the other times, Chris says he thinks Scott was on drugs.

"You name it, he did it," said Chris.

But it was when he was off his prescribed medications that Chris says Scott was at his worst.

"He always said the medication made him shake a lot and he couldn't sleep well. Some of the side effects from that, well he just had a lot of demons to deal with."

So, it seems did Seung Hui Cho who shot and killed 32 people at Virginia Tech last month before turning the gun on himself. Virginia Police told the Washington Post Monday that Cho never received the treatment ordered by a judge who declared him "dangerously mentally ill" two years ago.

But Chris says, Scott Barnaby did.

"We went to the judge and said he needs to be checked in," said Chris. According to Chris, the judge agreed.

Chris says his brother went to at least four facilities for treatment voluntarily including South Bend's Madison Center. But he says Scott was involuntarily committed to an institution in Grand Rapids.

Question 11-F on the federal background check Barnaby filled out asks: Have you ever been adjudicated mentally defective or committed to a mental institution?

Barnaby says his brother's answer to that question should have been 'yes.' However, we don't know yet how he actually answered the question. But just being treated for mental illness isn't enough to disqualify someone from buying a firearm.

"In the past, being adjudicated mentally defective -- found mentally defective by a judge -- that's been the key," said Brandt Schenken, Special Agent In Charge of the Bureau of Alcohol, Tobacco and Firearms' Cleveland Branch, whose jurisdiction also covers northern Indiana.

Still, Barnaby says his brother's past should have been enough.

"How many more lives need to be lost to wake up to the fact that easy access to guns is not helping this country, this community or this state?" he asked. "I don't know what the answer is. I really don't. But it's something that needs to be addressed."

Even if Scott Barnaby had been found mentally defective by a judge, Indiana state law would have prevented those records from showing up on his federal background check. However, Chris says Scott was also committed in Michigan, which does give federal agencies access to mental health records.

If convicted, the man who sold the gun to Scott Barnaby faces up to 15 years behind bars. Federal prosecutors say 71-year-old Ronald Wedge did not run a background check on Barnaby before he sold him the gun at a gun show in South Bend.

Licensed gun dealers are required to run a federal background check on anyone they sell a gun to, before the sale.

Wedge is charged with falsifying dates on the application.

Barnaby was eventually cleared for the purchase, a day after the officers were shot.