Adrienne Salinas Update: Boyfriend of missing Ariz. college student speaks out

(CBS) TEMPE, Ariz. - Francisco Arteaga, the boyfriend of Adrienne Salinas, an Arizona college student who went missing June 15, calls her disappearance "scary" and "the hardest thing ever," in an interview with CBS affiliate KPHO.

PICTURES: Adrienne Salinas: Missing Ariz. teen

Salinas was reportedly on her way to see Arteaga in the early hours of June 15 when she disappeared. The 19-year-old Salinas and her roommates at Gateway Community College in Phoenix had hosted a party at their Tempe apartment earlier in the night.

"[Adrienne] and her boyfriend got into a little argument, and she was going to go to his house," Shainey Duggan, one of Salinas' roommates, previously told the station.

Police in Tempe say Arteaga has cooperated with authorities and he is not a person of interest or suspect in the case.

Arteaga said he last heard from Salinas around 4:40 a.m. on June 15 - a half hour before her cell phone went dead - when she sent him a text reading, "I'm coming over."

But, she never got there, according to the station. Police say Salinas blew out the two front tires to her car just a couple of blocks away from her apartment. Cell phone records reportedly show the teen called a cab to pick her up at a nearby gas station, but she never made it there, either.

"It's the hardest thing ever," Arteaga told the station in an exclusive interview. "It's impossible not to think about her. It's impossible. There's never been a week where I haven't seen her. It's been three weeks now. It's scary."

According to the station, Arteaga and Salinas grew up together and had been dating on and off for several years. He reportedly described the missing 19-year-old as his best friend.

"We have so many childhood memories, so many memories," Arteaga told KPHO. "And, that's what's keeping me strong."

Since the teen's disappearance, friends and family members have plastered Tempe with posters of the young woman in hope that someone will recognize her and come forward with information. Tempe police have also searched the Tempe Town Lake and have joined forces with the FBI as well as police in Maricopa County and Scottsdale.

"It's impossible for her to have just vanished into thin air," Rick Salinas, Adrienne's father says, according to the station. "Somebody knows something. And, we're just pleading with that person, that someone, to just come forward and give us information so that we can get her back."

He says living without his daughter is like "living a nightmare."

"We can't waste any energy or thought on the worst-case scenario," Rick Salinas said. "I mean, there's no reason for that."

Arteaga echoed Rick Salinas' determination and hope.

"We're not going to give up until we find out what happened," Arteaga said, according to KPHO. "It's important that we keep the word out there. We have to. We're her only - we're her voice."

A $10,000 reward is being offered for her safe return.

Anyone with information about the disappearance of Adrienne Salinas is asked to call Tempe police at 480-350-8311 or Silent Witness at 480-WITNESS.

Complete coverage of Adrienne Salinas on Crimesider