(CNN) In the days and weeks after 19-year-old Marlen Ochoa-Lopez went missing in Chicago, frustrated relatives turned to religious leaders and community activists to help find the expectant mother.

Ochoa-Lopez's husband and her father told activists they did not feel police were doing enough to search for the young Mexican immigrant. She'd vanished April 23 after leaving Latino Youth High School to pick up her 3-year-old at day care.

"I believe we weren't taken seriously because we're undocumented," her widower, Yovani Lopez, told CNN.

Though officials stand by how they conducted the case, points of concern raised by Ochoa-Lopez's loved ones -- from the initial police investigation to protocols at the hospital where her baby remains on life support -- reflect the way authorities sometimes treat crime victims who are undocumented or impoverished, said community leaders helping Ochoa-Lopez's family and immigrant rights activists, who also confirmed her immigration status.

Justice Department investigators in 2017 described as "striking" the consistency with which residents of Chicago's "challenged communities ... expressed concern about the lack of respect in their interactions with police, whether those interactions come when they are targets of police activity or when they or their family members are the victims of crime." Latino residents also noted a sense of "guilt by association."

"This may not be how CPD intends policing to be conducted or perceived in these neighborhoods, but these experiences impact individual dignity and residents' willingness to work with law enforcement, and should not be ignored," noted the report by DOJ's Civil Rights Division , which helped form the basis of a federal consent decree that's guiding efforts to change police use-of-force and impartial policing practices.

Chicago Police Superintendent Eddie Johnson repeatedly has defended how his detectives dealt with the Ochoa-Lopez case, an extraordinary and shocking one that began with a report of a missing woman. Investigations like this one, he's said, don't often include the kind of dramatic revelations and gotcha moments seen on TV.

"Remember, this is real life," he said. "This isn't '48 Hours.' It doesn't work like that. It takes time."

Chicago police are also inundated with serious crimes, including gang violence and hundreds of homicides a year, said Maria "Maki" Haberfeld, a professor of police science at the John Jay College of Criminal Justice. That may have played a role in their decision-making, she said, adding that it does not appear the law enforcement response in this case was related to the family's immigration status.

"Unless there is something very tangible, police forces like Chicago that are overwhelmed ... tend to react in a slower mode," Haberfeld said, "especially when it comes to domestic situations when a husband or wife disappears. It takes time before the machine kicks in a higher responsive mode because it happens on a daily basis, and very frequently it has nothing to do with serious crime but rather some sort of disagreement within the household."

Ochoa-Lopez's relatives hold a news conference in mid-May seeking information about her disappearance.

As days dragged on after Ochoa-Lopez vanished, police repeatedly questioned Lopez about his wife's whereabouts and made him take a lie detector test, he recalled. Meantime, activists organized search parties, plastered missing-person fliers around the city's West Side and gathered anonymous tips.

"This illustrates how important it is, if we're going to protect victims and fight crime in our communities, for state and local law enforcement to build relationships with immigrants and limited-English-proficient communities and to take these cases seriously, just like they do any other case," said Leslye E. Orloff, director of the National Immigrant Women's Advocacy Project at American University Washington College of Law.

Indeed, not long after members of Ochoa-Lopez's community turned over their tips to police, the case's big break emerged.

Police superintendent: Investigators 'worked tirelessly'

Before police learned that the victim had gone to Figueroa's home the day she disappeared, they'd seemed to doubt that a random crime had been committed, said activists who helped Ochoa-Lopez's relatives spread the word of her disappearance.

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"They were downplaying the case because they had doubts about it," said Julie Contreras of the Latino civil rights organization League of United Latin American Citizens, or LULAC. "They were stereotyping the husband as a suspect and using stereotypes like, 'We think she ran off with a boyfriend.' It was just disgusting."

Yovani Lopez was never publicly identified by police as a suspect.

Chicago police spokesman Anthony Guglielmi last week defended investigators and seemed to expect official scrutiny of the department's actions.

"We will ensure that any complaint filed against the department is investigated independently and thoroughly," he said.

Guglielmi also acknowledged the "immense grief and suffering" of the victim's family, though police officials did not respond when CNN asked whether the case was treated differently because of the family's immigration status.

Detectives "worked tirelessly, following up on leads, interviewing witnesses and gathering evidence" in the search for Ochoa-Lopez, Johnson said.

"There's going to be anger associated," the superintendent told reporters. "When things of this nature occur, the first thing people do is look, in retrospect, what could we have done to maybe prevent this? I know our detectives do the best they can."

'We have to get the community involved'

Police learned through a tip that Figueroa had visited a Facebook page that helps families in need obtain baby items in order to lure Ochoa-Lopez to her home, said James Murphy, an assistant state's attorney . Figueroa offered the young mother clothes for the baby she was expecting in early May. On the page, Figueroa had pretended she was expecting a child herself.

When Ochoa-Lopez visited the home on April 23, Figueroa's daughter, Desiree, distracted the teen as her mother wrapped a cable around Ochoa-Lopez's neck, Murphy said. Desiree peeled the victim's fingers from the under the cable before her mother strangled the young woman to death, he said.

Marlen Ochoa-Lopez

The elder Figueroa then cut the baby from Ochoa-Lopez's womb, Murphy said. She later called 911 and said she'd just delivered a baby that wasn't breathing. The woman and infant were hospitalized at Advocate Christ Medical Center, though Figueroa showed no signs that might have suggested she had just given birth, according to the prosecutor.

Ochoa-Lopez's husband reported her missing on April 24, police said.

"I told them the truth the whole time," Lopez said of the police. "We had the problems that all couples have, but there were no big arguments or fights that would cause her to leave. I felt they were against me because I'm Mexican and undocumented."

Members of Ochoa-Lopez's family did not meet with detectives until nearly two weeks after she vanished, said Emma Lozano, pastor of Lincoln United Methodist Church. Lozano attended the meeting, which she said grew tense when some residents began chanting, "We want Marlen!" in Spanish.

Officers surrounded the residents and threatened to arrest them, according to Lozano, who calmed the situation by urging people to stop chanting. Chicago police did not respond to a request for comment about this claim.

After the meeting, the pastor did not harbor hope about the official search for Ochoa-Lopez, she said.

"This is not going to go well for us," she said. "We have to get the community involved."

Detective: 'I understand the anger the family is going through'

On May 4, activists took to the streets of the West Side, handing out fliers with Ochoa-Lopez's photo and a number to call with anonymous tips, Lozano said. The next day, they organized a search party.

"We knocked on doors, looked in dumpsters, went into abandoned homes," said Cecilia Garcia, a student pastor.

"Some detectives said our search as a community was a waste of time," said Jacobita Cortes, a pastor at Adalberto Memorial United Methodist Church.

"They would say, 'Marlen is very young, and she must have run off with someone or is staying with a girlfriend,'" Cortes said. "We told them, 'That can't be. She's about to give birth, and she has another child, and she's a good mother.'"

Chicago police did not respond to CNN's request for comment about Cortes' remarks.

Marlen Ochoa-Lopez's father, Arnulfo Ochoa, gets a surprise hug Wednesday from his 13-year-old son, Oscar, while visiting a mural of his slain daughter painted by Milton Coronado in Chicago.

Ochoa-Lopez's relatives and the activists believe police initially failed to dedicate enough attention to the disappearance because of the family's immigrant background, they said.

Then, as the community effort ramped up -- and Spanish-speaking police officers or interpreters were rarely available -- the activists became the main conduits to detectives, they said.

"We were doing to the investigation," Lozano said.

Her daughter, Sara Walker, a student pastor, added, "The police were not moving with any sense of urgency."

Indeed, a translator was assigned to the case at all times, Brendan Deenihan, deputy chief of detectives, told reporters. Detectives were in contact with the missing woman's family and friends from April 25 to May 7, trying to locate her and her car, he said.

"I understand the anger the family is going through," Deenihan said.

Investigators meet with reticent residents

Soon, local residents began calling in anonymous tips to the numbers provided on the fliers the activists distributed. Lozano fielded many of the calls. One anonymous caller said Ochoa-Lopez had entered the one-story brick house on the city's Southwest Side the day she disappeared, Lozano and Walker said. Ochoa-Lopez's car was later found near that home, where Figueroa lived. Her body was found in a garbage can behind the home on May 14.

Another caller said a middle-aged woman in the home had run out onto the street, claiming she had given birth but her baby was not breathing. The tipster said the woman did not previously appear to be pregnant.

The activists gave officers their leads, many from callers who were undocumented and afraid to contact the police directly, Lozano said.

Sill, police "said they were doing everything they could and following up leads," Lozano recalled one sergeant telling her.

"I said, 'What leads do you have?' And she read back to me the leads that I had called in. I said, 'How about her phone records?' Marlen's phone was still being used after she disappeared. They said, 'You can't do that. You have to get warrants, and all this takes time.'"

Contreras, of LULAC, arranged a meeting in the basement of a home between detectives and about nine residents who were reluctant to talk to the police because of their immigration status, she said.

Immigration advocates have said the Trump administration's hardline enforcement has heightened undocumented immigrants' reluctance to work with law enforcement. But Chicago is a so-called sanctuary city, a broad term applied to jurisdictions with policies that limit police cooperation with or involvement in federal immigration enforcement actions. Cities, counties and some states have a range of informal policies and laws to this effect.

"I gave each resident a lecture and spoke with each one to say, 'Today, it was Marlen's family, and tomorrow it could be your family, and imagine if somebody said they didn't want to help," she said.

Relatives want to know if rules were skirted

On May 7, armed with the tip about Ochoa-Lopez's Facebook exchanges with Figueroa, detectives visited the defendant's home. The lead was the product of Contreras and Lozano's community outreach, they said. A police spokesman did not respond to a request for comment about this.

Desiree Figueroa told detectives her mother was in the hospital for problems with her legs. Then, she revealed that her mother had just delivered a baby, police said.

When detectives interviewed the elder Figueroa at the hospital, where she had been admitted after claiming to have given birth, she denied Ochoa-Lopez came to her house April 23 but admitted to meeting her in the past, police said.

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Suspicious, officers spent the next several days securing subpoenas for hospital records and collecting DNA samples from the baby and Figueroa. They discovered she was not the child's biological mother; the tests showed Lopez was the father.

Clarisa and Desiree Figueroa were charged with first-degree murder and aggravated battery of a child younger than 13 years old. Clarisa Figueroa's boyfriend, Piotr Bobak, 40, has been charged with concealing the death of a person and concealing a homicidal death; all were still being held last week without bond, and it wasn't clear whether they had attorneys. A medical examiner determined Ochoa-Lopez died of strangulation.

Illinois law requires that physicians and other hospital personnel who suspect child neglect or abuse report their suspicions. Lopez and the activists want to know whether the hospital followed protocols, they told CNN.

The Illinois Department of Public Health is investigating Advocate Christ Medical Center, spokeswoman Melaney Arnold confirmed this week. She declined to provide additional information, citing an ongoing probe. A hospital spokesman told CNN this week he could not comment on the case.

The state Department of Children and Family Services was not contacted by the hospital until May 9, one day after police found Ochoa-Lopez's car, agency spokesman Jassen Strokosch told CNN. Hospitals are mandated to report to DCFS under the Abused and Neglected Child Reporting Act if there is concern about a child, he said.

The Cook County Sheriff's Office "will consult with DCFS on whether the circumstances of this case required DCFS be notified," the agency said in a statement obtained by CNN affiliate WGN. "If DCFS says they should have been notified, the sheriff's office will conduct an investigation into what happened."

'The city of Chicago needs to awaken itself'

Ochoa-Lopez's baby boy remains in intensive care at the hospital, listed in grave condition and fighting for his life. He is surrounded most of the day by his father, grandparents and other relatives who traveled from Mexico on humanitarian parole for his mother's funeral.

Meanwhile, Contreras is drafting a public information request for the Chicago Police Department, citing the community's complaints about the case and demanding all records on the availability of Spanish-speaking officers and interpreters, as well as other policies, training, operations and procedures related to contacts with the Latino community, she said.

LULAC plans to file a formal complaint after a reviewing of the records, she said.

Mourners embrace on Saturday at Ochoa-Lopez's funeral in Chicago.

As loved ones gathered Saturday for Ochoa-Lopez's funeral, they vowed something more: a bill, dubbed Marlen's Law, that would aim to require "any individual who enters a hospital ... to provide identity through ID and DNA to prove (their identity), if they come in with an infant they say is born in their home," Contreras said.

"She is the daughter of our pueblo," the activist said, "and she will be etched forever in the laws."

Addressing the mourners, Contreras, her volume rising, also nodded to the treatment she and others have said they felt the case got from the authorities.

"And the city of Chicago needs to awaken itself," she said. "If there is a place where you are not respected because of your accent, instead of your intelligence, don't accept it.

"Marlen is the example of that. Do not accept it," Contreras said. "She is the seed in the middle of this tragedy that will create miracles."