Delia D'Ambra

I mean, after all, they had used Paula's truck to go camping, and she told reporter Emily Bittner that it would have been out of character for Lisa to stay another night in the desert without at least calling her mom first.

Initially, Paula wasn't even sure if she even wanted to let the couple use her truck because she knew it needed an oil change and Lisa had never really gone camping overnight in the desert before.

But eventually, she relented and told them they could take it.

When the pair didn't return and time kept ticking by, Paula said that she felt a sense of dread wash over her.

She later told KPNX reporter Rachel Cole that it was about 9 o'clock in the morning on Saturday when she checked her watch and suddenly began crying.

Her son, who was with her at the time, asked her why she was so upset, and Paula told him she just knew in her heart something was terribly wrong.

After that, she contacted the Mesa Police Department and then called Brandon's father, Rob Rumbaugh, and a few of the couple's close friends.

When Saturday afternoon turned into evening and Brandon was a no-show, no-call at work, all the red flags were up at that point, and their families had officially reported them missing.

According to Paula, loved ones could not get any immediate help from park rangers or anyone in a position of authority to organize a formal search.

So they just went out on their own that Saturday to look for Brandon and Lisa.

The group checked several roads and paths in the desert and the general vicinity where the couple said they were going to be, but no one found them or Paula's truck.

According to Brian Wells' reporting for the East Valley Tribune, on Sunday morning, Brandon's father checked his son's bank account activity and didn't see any recent transactions, which seemed to be another indication that something was amiss.

Multiple calls to the couple's cell phones were never able to get through because every time someone dialed Brandon or Lisa's numbers, a no-service message would play, indicating that wherever their devices were, they were not in an area with good cell phone reception.

It wasn't until the murders were discovered that Lisa and Brandon's absence and all these other things made sense.

It was difficult for people who knew the young couple to think of anyone who would wanna harm them.

Paula told the press that neither of the victims had enemies, and Brandon's mother, Desiree, further suggested in comments she made that whatever happened to them seemed to be a random act of violence.

That theory, as frightening as it was, was a scenario law enforcement considered.

A lieutenant for the sheriff's office told the press, "...do we believe that this was a random act and that there's a crazy person running around?

Not necessarily.

Can we rule it out?