The search is on for a missing teenage couple from San Antonio.

Yesterday, the Bexar County Sheriff's Office released photos of 15-year-old Joshua Dixon Koob.

Thursday afternoon, his girlfriend, 17-year-old Audrey Taylor, was also reported missing.

Investigators believe the couple is together right now, perhaps traveling.

Family members are concerned for their safety.

Koob was last seen July 7 at his home in the 11400 block of Lago Vista on the northwest side.

He lives with his grandmother.

Family members say he has never run away from home before.

Taylor just moved from the northwest side to the Windcrest area.

Her mother, Sarah Price, spoke with us over the phone Thursday.

"[Audrey] and Josh were at a friend's house together Saturday," Price said. "When I picked her up, Josh was there."

Sunday night, Price says police came knocking asking about Koob. Taylor said she didn't know where he was.

"She went to bed and I went to bed, and in the morning when I left she was not here. I have not seen her since then," Price said. "I called police because I figured she ran away with him."

Officials said they don't highlight one case over the other.

"If it's out of character, you need to let a law enforcement agency know," Sandra Pickell, Spokeswoman for the Bexar County Sheriff's Office said.

Investigators look at patterns. Has the minor run away before? Does the adult have a medical condition?

"There is no wait time or no certain amount of time that a person should wait to make the report," Pickell said. "Why is that important? Perhaps the person might be in danger."

Regardless of the amount of time, if an unfamiliar minor is inside your home, authorities suggest calling their parent or guardian.

"If you are not 100 percent sure who this person is, who their parents are, who has custody, who doesn't have custody, that person should not be in your home," Pickell said.

Keep in mind, if someone knows police are looking for a specific minor, and they still let the minor stay in their home without telling anyone, they could face criminal charges for harboring a runaway.

Koob is described as 5 feet, 7 inches tall, 120 pounds, with brown hair and brown eyes.

Taylor is 5 feet 3 inches tall, 105 pounds, with brown hair with green tips and brown eyes.

If you have any information on the whereabouts of these teens, call the Bexar County Sheriff's Office Missing Persons Unit at 210-335-6078 or the BCSO Tip Line at 210-335-TIPS (8477). You can remain anonymous.