HOUSTON -- Tens of thousands of master key boxes can be opened by convicted felons in the Houston area, as well as thousands more statewide. Now, Austin is moving into action because of a recent KPRC Local 2 Troubleshooter investigation, the station reported Monday.

"(It's) very frightening. I mean, it's very frightening to think that someone could get that master key and go to where students are living, go where they're going to be in contact with children," said State Rep. Geanie Morrison, R-Victoria.

The Troubleshooters spotted a registered sex offender with a master key and saw his list of house calls. He visited eight homes in one day.

One of his stops was a west Harris County home. Robert Casados, who pleaded guilty to sexually assaulting a child, used his key to set up a lockbox at a home where a young mother and baby were alone.

He also copied other house keys at a locksmith.

"Well, I think that this is something, especially in light of today, that we definitely need to look at, because, there again, the public trust is that when someone comes into your home, that you feel like they've been screened," Morrison said.

The state representative serves over the committee overseeing all state licenses and she called the Troubleshooters investigation disturbing because it was not just realty workers the station found with sexual assault, aggravated robbery and other convictions.

Hidden cameras found a pest control worker using a master key despite a criminal record.

Heating and air conditioning contractors got into a house near Alief.

And home inspectors carry some of the 19,000 master keys in the Houston area.

"Your investigation brings forth those circumstances, while they may be few and far between, brings forth those instances where lawmakers might throw up their hands and say, 'We're not going to have this happen,'" said State Sen. Kyle Janek, R-Houston.

It's happening because of the licensing guidelines at state agencies such as the Texas Real Estate Commission in Austin.

"I think we would certainly welcome more direction in that regard," said Loretta DeHay, the Texas Real Estate Commission general counsel.

DeHay said the reason the Troubleshooters found master keys being carried by ex-cons is because state agencies are required by law to consider the good things about murderers, rapists, and other criminals who want licenses.

But Janek said the law should be changed now.

"That means we've given that particular licensing agency too much leeway and I think it's the duty of the state to say, 'We'll make it clearer for you -- no rapists, no violent criminals, certainly no murderers can hold a license,'" he said.

"Why didn't y'all do that (say) 'Hey, let's not grant a license to sex offenders, period.' Why wait on the legislature?" Troubleshooter Stephen Dean asked.

"Well, if we had the absolute power to do that, we could," DeHay said.

The head of the real estate commission now wants all the backgrounds of all 140,000 licensees to be rechecked because of the Troubleshooters' reports.

The agency is already moving to revoke the license of sex offender and realtor Darren Slawson. The Troubleshooters reported last week that he applied for his license, saying he had never been on probation. But his probation had started one month earlier.

"You pleaded guilty to sexually assaulting a child. The real estate commission asked you if you'd ever been on probation. You were on probation at the time," Dean said.

"You guys must have a slow news day to be interviewing me," Slawson said.