PHOENIX (3TV/CBS 5) -- At least four times in the past two months, serial rapists or men suspected of being serial rapists have made headlines in the Phoenix area.

In three of the four cases, the key to linking the crimes to the suspects was a DNA profile uploaded to a national database of unsolved crimes. It is a relatively new approach to solving sex crimes that appears to be paying off as more profiles are uploaded to the database.

[WATCH: "We are submitting all sexual assault kits to a crime lab"]

"It's useful that we are at a point, at least here in Arizona, where we are submitting all sexual assault kits to a crime lab, including those kits that were previously not submitted," said Tasha Menaker, who is the co-chief executive officer of the Arizona Coalition to End Sexual and Domestic Violence.

"Because it's allowing us to enter more DNA into the database and make connections across cases, across offenses that we not would not have been able to do otherwise," she said.

[RELATED: Maricopa County untested rape kits now fewer than 300]

In March, a Tucson man named Nathan Loeb was convicted of raping seven women over 12 years. Several of the rape kits taken from his victims were not tested or submitted right away because investigators used to put less of a priority on allegations of sexual assault where consent was at issue. Loeb's victims met him at bars and through online dating sites.

[MORE: CBS 5 Investigates]

In April, Scottsdale police connected a Chandler man named Abbas Shemisawi to two rapes through DNA profiles.

[THAT STORY: Cab driver arrested after DNA links him to Scottsdale sex assault]

"We get a notification that our profile matched a profile in a case out of Phoenix, a sexual assault out of Phoenix," said Kevin Watts, who is a spokesman for Scottsdale Police.

And this week, Christopher Van Buskirk from Goodyear was arrested and charged with six rapes that occurred in California.

[THAT STORY: DNA links Goodyear man to string of rapes in Southern California]

A research study conducted by Case Western Reserve University in Ohio in 2016 found that serial rapists are more common than previously thought. They accounted for 51 percent of the assaults that researchers studied. In addition, they found that serial rapists generally do not have established patterns or victim "types."

"What they found was that they were actually pretty diverse in terms of perpetrating both against people who they knew and people they didn't know. Perpetrating in multiple jurisdictions and sometimes in other states," said Menaker.

But Menaker also cautions that the study and recent arrests may be outliers, because a vast majority of victims, 70% to 90%, never come forward.

"Of those cases that do get reported, only about 2% end in a conviction," said Menaker. And in most cases, she says, the victim knows the attacker.

"What I had to do was find out what justice would look like for me outside of the criminal justice system. So for me, personally, that meant doing well in school. It meant graduating," said Jacquelyn Hinek, who reported being sexually assaulted by members of the University of Arizona football program in 2013. Her attackers were never prosecuted.

"Something that the detective told me when my case was wrapping up was that, 'Everyone in the department believes you, and we know that they did this to you.' But then when it came to the point where it was going to be potentially picked up for prosecution, they said, 'Well we're just not going to be able to prove this,'" said Hinek, who now works as an advocate for sexual assault survivors in California.

The facts of her story are unique, but the outcome is all too common. But things may be starting to change. Advocates say police are submitting more DNA profiles to the national database, resulting in more serial offenders getting caught.

The 2018 Annual Report of Sexual Assault Kits, published by the Arizona Department of Public Safety, found that 87 percent of rape kits obtained were subsequently submitted to a crime lab for analysis.

Morgan Loew's hard-hitting investigations can be seen weekdays on CBS 5 News at 6:30 p.m. and 10 p.m.

Copyright 2019 KPHO/KTVK (KPHO Broadcasting Corporation). All rights reserved.

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