ROYAL CITY - Evidence in the case of the 16-year-old Royal City girl who has been missing since last week suggests she willingly left with Miles "Logan" Moncada.

Monica Helberg went missing sometime Wednesday or Thursday and is listed as an endangered missing person because she is without her asthma medication. The sheriff's office is considering this a runaway juvenile case based on evidence showing that Helberg and Moncada were previously in a relationship and Helberg ran away with him once before.

The sheriff's office also reported Helberg's parents received text messages from her phone, and believe one of Moncada's family members met with the two early Thursday morning in Moses Lake and gave Moncada his wallet.

When Helberg was found missing Thursday morning by her parents, pillows on her bed were arranged to appear as if a person was under the covers.

Moncada was reportedly spotted Saturday night at an Albuquerque motel, where law enforcement found hair dye and disposable razors, suggesting the two may have changed their appearance.

The sheriff's office and other law enforcement agencies continue to work to find Helberg. The U.S. Border Patrol was given photos of the two in case they try to enter Mexico.

The sheriff's office is also preparing reports to forward to the prosecutor's office to determine if any charges of unlawful harboring of a minor, a misdemeanor crime in the state, against Moncada are appropriate.

The FBI is also monitoring the case but based on the law there is nothing that can be done at this time. If an arrest warrant is issued for Moncada, the FBI can review the case to determine if there is evidence to suggest Moncada was fleeing to avoid prosecution, according to the sheriff's office.

Moncada and Helberg were believed to be traveling to Texas where Moncada has family. Police in Texas have photos and case information and are on the lookout for the 2014 Ford Focus they are traveling in. Law enforcement is not able to track the vehicle using GPS because the vehicle does not have that ability.

Anyone with information that may be helpful in finding the two are asked to call their local law enforcement agency. For those in Grant County, the sheriff's officer requests tips to be called in to the Multi-Agency Communications Center at 509-762-1160 and ask for the on-duty sheriff's supervisor.

"We ask people with tips to please not call a specific deputy that they may have had contact with in the past. Doing so has caused duplication in our efforts and oftentimes delays in response as some deputies may be off duty," a sheriff's office official said in a press release. Tips can be sent to crimetips@co.grant.wa.us.

The sheriff's office received an "overwhelming" amount of calls from people just seeking updates on the case, hindering law enforcement's ability to prepare reports and coordinate efforts with other agencies.

"Monica's parents are still very concerned about her and hope she contacts them soon," the sheriff's office official said. "As you can imagine, this is a difficult time for the Helberg family and any assistance is appreciated. It is still very important that Monica can confirm her well-being."