CHICAGO (CBS) -- The man charged withlast month, and suspected in the murder of a Chicago teacher, also has been accused of attacking another woman in 2021.
CBS 2's Marissa Perlman is always investigating, and has more on the pattern of violence dating back years.
"She was afraid. I know she was. We can feel it," said the niece of Adrianna Lopez, an elementary school teacher who was shot and killed last month. Lopez's niece wanted her identity concealed, but she also wanted to speak out for her aunt, who she said was living in fear of her ex-boyefriend.
Lopez's ex-boyfriend, known by the name Cristobal Santana, is, but has not been charged in that case. He is being held on unrelated charges of shooting a state trooper in Springfield last month.
In September, just weeks before she was slain, Lopez went to Chicago police for help, filing a police report accusing Santana of attacking her.
"She basically had the mindset of 'I don't know what this man is capable of doing next,'" Lopez's niece said.
Lopez likely didn't know what Santana was accused of doing just two years earlier to another girlfriend; a woman named Erika, living in New Orleans, who also went to police for help. Two women in two states accusing the same man of eerily simliar attacks.
Amanda Pyron, who heads The Network – a nonprofit that works with domestic violence survivors – reviewed both police reports.
"The patterns of violence are very similar, and that's what we often see in these cases – is that domestic violence increases in frequency and intensity over time," she said.
In a New Orleans police report from 2021, Erika said Santana "punched her in the left eye." An officer noticed her eye was red and swollen.
Before that attack, Erika told police Santana "posted private pictures [of her] online," and said he "broke my arm."
Then, two years later, Lopez filed a Chicago police report, saying Santana "punched...[her] in her face twice" and punched her in the ribs as well.
Those documents also showed Santana wasn't prosecuted for either attack.
"Often when law enforcement officers respond to the scene of these incidents, they don't do anything," Pyron said.
Though he wasn't prosecuted in New Orleans, Santana was arrested. The report shows officers even took his handgun – a Glock. They kept it for months, but when he wasn't charged, they gave it back.
It's unclear whether it's the same weapon Santana is accused of using to shoot and seriously wound Illinois State Police Trooper Dakota Chapman Green in October. Santana has been charged with two counts of attempted murder, two counts of aggravated battery, and one count of unlawful use of a weapon in that shooting.
Meantime, another similarity tying Lopez and Erika together is that both filed for protective orders against Santana.
Erika's was filed first. Her report goes said she and Santana "have a documented history of domestic abuse in Chicago."
Did Chicago police know about the New Orleans report? Chicago police said they have no records involving Santana.
"There is a lot of changes that could be made in systems nationally and locally that would prevent this, but unfortunately without arrests, without prosecutions – especially domestic prosecutions – you're not going to have that paper trail," Pyron said.
There's something else there was no record of in Lopez's police report - no mention of Chicago police officers ever questioning Santana. They simply told Lopez how to get a protective order.
"You would think that they would question the person accused of causing harm," Pyron said.
Perlman: "What would your message be to law enforcement and prosecutors when you see these two reports involving the same man not prosecuted?"
Pyron: "I think we can do better."
Pyron and other advocates believe there should be a national database tracking domestic violence incidents.
Oftentimes police departments won't see when someone is charged if they're not convicted.
Again, Santana is not facing charges for Lopez's murder.
But this case takes yet another chilling twist. Monday night at 10, CBS 2 will also introduce you to the man who says he is the "real Cristobal Santana," and how he has been haunted by this suspect for years.
We will share records that led us to him, more than 700 miles away from the Chicago area.
for more features.