The San Antonio Strangler: South Texas Crime Stories

‘For him, it was pleasurable to talk about [his crimes] and to tell about it,’ a detective on the case said.

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He ripped five women away from their families, many more narrowly escaped his grasp.

In the middle of the night, he’d stalk his prey before attacking.

KSAT12's Erica Hernandez joins GMSA@9 to talk about the San Antonio Strangler case.

Natalie Chavez

Natalie Chavez was only 15 years old when she ran away from home in 2014. She was gone for a few months and was never reported missing by her mom or stepdad.

She tried to reach out a few times to ask if she could come home, but messages went unanswered.

“She’s run away before. We’ve got a missing persons report on file for her from some time ago. She was not reported missing, though, when she was murdered,” SAPD police chief William McManus said in 2014.

On December 17, 2014, Natalie sent another text to her stepfather, saying she was ready to come home and that she loved him.

Her family never answered that message.

“And I felt like maybe if we would have answered. There’s a lot of what-ifs. If we would have answered, maybe this could have been avoided,” Carlos Johnson, Natalie’s stepdad said in 2014.

The teen’s body was found the Dec. 18 at 10 a.m. under a bridge near the intersection of Vera Cruz and Nueva Leon St.

“She was a very good daughter. We miss her a lot already,” Johnson said.

SAPD said she was found naked, the medical examiner said her cause of death was asphyxia, meaning she was likely strangled.

Police started looking for who was responsible for Natalie’s death, they had one big help in the case, DNA.

That’s what led them to then 28-year-old Johnny Joe Avalos.

Johnny Joe Avalos

Johnny Avalos was arrested on April 21, 2015, on a charge of sexual assault of a child based on the DNA evidence found on the body of Chavez.

Investigators also believed that he was responsible for her death but they didn’t have enough to nail down their case yet.

According to the arrest affidavit, Avalos told investigators he had sex with Chavez for a “predetermined amount of money” but that he wasn’t aware of how old she was.

Then police chief Anthony Trevino said Avalos was a person of interest in two other disturbing cases.

Celia Lopez

On April 15, 2015, Celia Lopez age 29 was found dead in the 4400 block of South Presa.

She had suffered trauma to her head and face.

Genevieve Ramirez

Just 11 days earlier on April 4, Genevieve Ramirez was found unconscious in a grassy alleyway in the 100 block of Avondale Avenue.

According to SAPD, she was nude from the waist down and had bruising but no obvious signs of trauma.

Ramirez was hospitalized but died from her injuries two months later.

Rosemary Perez

Court documents revealed that on or around January 10th, 2015, Avalos killed 28-year-old Rosemary Perez by asphyxiation her with his hand and arm.

It took a year and seven months, but then-Bexar County District Attorney Nico LaHood handed down two indictments alleging Avalos had killed four women between December 2014 and April 2015.

The indictments say Avalos strangled each victim with his hand and arm, also using plastic bags on three of them.

Later in court, it was revealed that Avalos’ killings stretched back to October 2012.

Vanessa Lopez

His first victim is believed to be 25-year-old Vanessa Lopez.

She was found in the San Antonio River in a portion of Mission Reach. Investigators believed she had been in the water for several days before she was found.

Court records introduced in February 2019 explained that Avalos would stalk women, primarily sex workers, in the middle of the night on the South Side after he got off work as a dishwasher at a restaurant near downtown.

Avalos claims at least 20 other women he tried to attack got away.

In court, Avalos plead guilty to the capital murder charges against him and was sentenced to life in prison without parole.

He was evaluated and determined to be intellectually disabled, because of this prosecutors opted not to seek the death penalty against him.

Assistant DA David Lunan explained that the definition of intellectually disabled is determined by state law and begins with an IQ examination, with 70 or below as a starting point.

“We look at the IQ and then combine that with looking at what other adaptive deficits have been demonstrated,” he said.

Lunan went on to say other considerations include cognitive reasoning and judgment abilities.

Given Avalos’ intellectual status, to execute him would violate his Eighth Amendment rights that guarantee protection from cruel and unusual punishment.

SAPD Detectives who helped capture Avalos

We sat down with SAPD Detective Mark Duke, who worked on Vanessa Lopez’s case, and Detective Leroy Carrion, who worked on Natalie Chavez’s case.

Detective Duke is the only active trained criminal profiler in the state of Texas, he’s trained under the FBI’s Behavior Analysis Unit, Texas Rangers, and the Florida Department of Law Enforcement.

That fellowship training took 5 years to complete. He’s been with SAPD for about 27 and a half years and a homicide detective for 12.

Detective Carrion joined the academy in 1994 and graduated the following year. In 2008 he was promoted to detective and that’s where he’s been ever since in homicide.

“I knew the condition of the surroundings, how we found Natalie... it was going to be difficult. I knew what we collected at the scene was going to be very important... to identify who did this. And then, of course, the crime lab was huge in this and this particular case,” Detective Carrion said about Chavez.

“She washed downstream about seven miles and was recovered in a spot, a park. So we believe that was his first homicide. That’s what he says. And we don’t have any reason to not believe that, although we do know that they only tell us what they want to tell us. And, you know, we have to work through that and try and get evidence that matches that. You have to let the evidence drive the case. But we believe she was the first one that he killed,” Detective Duke said about Lopez’s case.

Duke explained when speaking to Avalos after he was in custody, Avalos found an odd pleasure in describing what he did.

“There’s only three ways to solve a crime, and that’s physical evidence, eyewitness testimony or a confession. And physical evidence only leads to arrests and successful prosecution about 13% of the time. So that means that 80-plus percent of other crimes that are solved come from the other two eyewitness testimony or confessions,” Duke said. “He’s a different animal, the type of person he is. He enjoys reliving these events in his life. And so for him, it was pleasurable to talk about it and to tell about it. And you can even see it on his face when he was reliving it.”

Shortly after Detective Carrion started work on Natalie’s case, there was another death. Carrion had a gut instinct that there was a connection so he started to collaborate with another investigator.

“There’s a link. I said, let’s send off what your findings are with our findings and submitted to the crime lab and see if there is a match. And, there was, and that kind of (hinted that) there’s more victims. And I started reaching out to go to all the detectives in the office. Do you have a case that kind of matches a female? Kind of matches the profile of a victim and. And. Boom. There was. We found several others,” Carrion said.

When that DNA matched Johnny Avalos, both Carrion and Duke were surprised. He was never someone on their radar.

“We all wanted to know; who is this person? He’s out there hurting these girls and leaving them the way he did. It was was violent. What motivated him to do that? You know, you’re kind of thinking yourself about the person you’re dealing with,” Carrion said.

Life in prison

Avalos will never be released from prison, a fact both Carrion and Dukes are thankful for.

“To be able to put somebody in jail and for him to get convicted with the only satisfaction I really get is just I know that there’s not going to be another victim that we’ve done our part to, to hold our communities, hold our women, young women, all women a little bit safer knowing that he’s not going to hurt them,” Carrion said.

“You’ve got to be working for something bigger than yourself and just feel like you just have to have a strong desire to do what’s right. Because there’s no there’s no fan club. There’s no, there’s no fame or fortune coming,” Duke said.

Detective Dukes had a message for anyone who has thought about committing a crime as horrendous as what we saw Avalos do.

“Nobody does wrong things and always gets away with it. Eventually, you’re going to get caught. It may not be the day. It may not be next week. But it’s coming. And that closes doors for you that’ll never open again. So think long and hard about the consequences of your decisions,” Duke said.

When working these cases, detectives form relationships with their families. Detective Carrion has a lasting relationship with Chavez’s mom and stepfather.

“We’re still thinking of Natalie and it’s tough. She’s a young girl. What was done to her was just horrible,” Carrion said. “A mom lost her daughter. And she was taken, she was taken from her, taken from all of us. Yeah, that motivated me then, it still does now.”

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About the Authors:

Erica Hernandez is an Emmy award-winning journalist with15 years of experience in the broadcast news business. Erica has covered a wide array of stories all over Central and South Texas. She's currently the court reporter and cohost of the podcast Texas Crime Stories.

Leigh Waldman is a news reporter at KSAT 12. She joined the station in 2021. Leigh comes to San Antonio from the Midwest after spending time at a station in Omaha, NE. After two winters there, she knew it was time to come home to Texas. When Leigh is not at work, she enjoys eating, playing with her dogs and spending time with family.