TULSA, Oklahoma - After a sex offender is released from prison, they are supposed to register their home address with law enforcement. Those addresses are put into a statewide map so the public can know where they're staying.

But some Tulsa offenders are avoiding detection- by simply registering as "homeless."  

Most days you can find Rikki Motes catching the city bus in downtown Tulsa.

Sometimes, she has her three children with her, so you can imagine her reaction when she found out a wanted sex offender has been seen in the area.  

"That's kind of, kind of scary," Motes said.

Dwight Johnson hangs out in downtown Tulsa. He's a convicted sex offender who spent seven years in prison for the crime he committed. After he was released in 2008, he registered as a sex offender and listed himself as "homeless."  

Usually when someone registers, they're required to provide an official home address. But if they register as homeless, that rule doesn't apply. 

Tulsa police detectives say this is a tactic some sex offenders use to try and stay under the radar. Sex offenders who register as homeless do not show up on the state sex offender registry mapping, so searching online, you would never know if they are staying in your neighborhood

"We have a lot of sex offenders who try to register as homeless," Tulsa Police Sgt. John Adams said.

In Tulsa, if a sex offender registers as homeless, they're required to check in with a detective once every seven days to give them a general idea of where they'll be. 

"If you want to register as homeless, we'll register you as homeless, but we will definitely come look for you and we will definitely arrest you if we can't find you," Adams said.

"If we don't find them in the three to four checks, we will file for a warrant and do a probable cause arrest the next time we find them," he said.

Undercover detectives say they haven't heard from Johnson in months, so now they are trying to arrest him.  

It is particularly concerning for Motes. She, like many others we spoke to, wishes there was better notification when sex offenders frequent an area.    

"They have transit police around here," she said. "I mea,n they could post pictures somewhere, bulletin boards or something like that where people could recognize them."

Right now, there are 336 registered sex offenders in Tulsa. Eleven of them are listed as homeless. Recently, detectives arrested six homeless offenders on "failure to comply as a sex offender" after they stopped checking in. If charged and convicted, they could face up to five years in prison.

Detectives say they continue to monitor sex offenders using tactics and technology they can't disclose to the public. Some are currently pushing for ankle bracelets for homeless sex offenders. 

They say these would allow them to monitor their movements, making it a lot easier to find someone like Johnson, whose whereabouts are still unknown.

The Tulsa Police Department says around 200 sex offenders have failed to register at all, meaning their whereabouts also are unknown.