Audrii Cunningham missing: Person of interest last to see girl in Texas before disappearance

HOUSTON -- Authorities say they have not lost hope as they reach the fifth day in a desperate search for missing 11-year-old Audrii Cunningham near Houston, Texas on Monday.

There has been no sign of Cunningham since last Thursday, when she was supposed to be dropped off at her bus stop but never made it. She was last seen around 6:45 a.m. near her father's home. Her disappearance led to a statewide Amber Alert being issued the same day.

Since then, 42-year-old Don Steven McDougal, a person of interest in her disappearance, was arrested Friday on an unrelated aggravated assault charge and booked into the Polk County Jail. ABC Houston affiliate KTRK learned McDougal is Cunningham's father's roommate.

In an afternoon press conference Monday, the Polk County Sheriff's Office and Texas DPS gave the latest information on the case. They are asking the public for video showing FM 3126 from Thursday, between 6:30 and 8 a.m., and increased the award for information leading to an arrest in the case to $10,000.

McDougal lives in a camper behind Cunningham's home and is said to have a relationship with her family. Officials said he was the last person to see her, adding that he would occasionally drop off the 11-year-old at the bus stop.

Polk County Sheriff Byron Lyons said McDougal has been cooperating and taking investigators to search certain areas, but he has not confessed.

Search crews could be seen going up and down Trinity River in Polk County over the last couple of days.

Authorities said they searched several locations over the weekend, finding a backpack believed to belong to Cunningham but no sign of the 11-year-old.

During Monday's press conference, authorities also addressed McDougal's criminal history. He was convicted of enticing a minor in 2008 but was not required to register as a sex offender.

Investigators said a vehicle of interest belongs to McDougal but added they have not ruled anyone else out who may be involved.

"One of the things that we must do is that we must not jump to conclusions. We want to make sure that we take all the evidence that we have collected. Yes, he (McDougal) may have been the last person with her, and yes, she is missing at this time. But we want to make sure that whatever evidence that we collect and that we place on an affidavit today is going to be something that's going to hold up in the court later," Lyons said.

Anyone with information on Cunningham's disappearance is urged to call the Polk County Sheriff's Office at 936-327-6810.