If the threat is immediate, then absolutely, yes.

“When you witness a child who is in immediate danger, and there is no adult mitigating that danger, the police are the appropriate first responders,” said Ellen Smith, associate director of the University of Wisconsin-Madison’s School of Social Work.

Law enforcement can respond immediately; child protective services could take up to 24 hours.

Maybe you see someone physically hurting a child, said Dr. Jamye Coffman, medical director for the Center for Prevention of Child Abuse and Neglect with Cook Children’s in Texas. Or you hear unsettling screams from the apartment next door. If you’re genuinely concerned that a child is in harm’s way, it is your responsibility to call law enforcement right away.

Other examples may not be immediate threats, like a child running away from home to a friend’s house, a child being publicly disciplined, or a child who looks like they need food or clothing. They may require intervention, but not necessarily calling 911.

Nine out of every 1,000 children in the U.S. are subject to physical, psychological or emotional abuse, or neglect that is reported to — and substantiated by — CPS. Experts say many cases of abuse or neglect go unreported, however.

“Abuse is generally a crime of isolation,” said Coffman. Children lack the ability to report it themselves, and could suffer even more if they do. And many people simply do not know when it is appropriate to make a call about suspected child abuse or neglect, or how to do so.

All states have a government agency charged with handling reports of suspected physical or sexual abuse, or neglect — which can include a child not having their basic needs of food, shelter and supervision provided. In many states and localities, that agency is called Child Protective Services; other places may have slightly different names for the same function. Each state has a hotline number to call if you are concerned about a child. In much of the U.S., individuals who report suspected abuse or neglect in “good faith” (meaning you’re not knowingly making a false report) are granted some level of immunity from prosecution, and most states allow for anonymous callers.

Smith explained it this way: The police’s role is supposed to be to intervene in — and investigate — criminal acts. CPS also intervenes, but it also works to ensure children are in a safe environment in the future. Anyone can call CPS to offer observations or information about what they believe to be abuse or neglect. Reports are then “screened in,” meaning the state agency has determined there’s enough information to proceed with an investigation, or “screened out,” meaning the report doesn’t rise to the state’s legal definition of abuse or neglect, or there’s simply not enough information for CPS to act on.

There’s a fair amount of research casting doubt on how these agencies affect children’s long-term prospects, including a 2010 study that found that launching an investigation into suspected child maltreatment did not necessarily improve the lives of children long term.

To that end, some experts have argued that to really help kids in crisis, police should be called in to investigate abuse. There should also be a bigger role for public health nurses in investigating chronic neglect, and social workers should take the primary role in providing kids and families with ongoing support.

Making a call to CPS is a very big deal. When you pick up the phone, you’re starting a process that has the potential to rip families apart. If you do suspect abuse or neglect, you should seriously consider the potential outcomes before calling CPS. A parent’s struggle with substance abuse, for example, does not mean a child will be maltreated. Poverty is not the same thing as neglect.

“If our system was able to work properly, we would encourage people to call child protective services whenever they suspected a child was being abused or neglected,” Smith said. “It is the job of CPS to know how to screen out inappropriate calls and to be able to interview the callers and gather enough information to decide whether or not the situation is really in need of child protection.”

A major criticism of child services in the U.S. is the pronounced racial disparity in the system. Estimates suggest, for example, that more than 30% of kids in foster care are Black, even though Black kids are just 15% of the U.S. child population. Nationally, families of color are far more likely to be reported for suspected abuse and neglect.

The “why” is complex. How much of it is tied to underlying factors like poverty, and how much is driven by racial bias? Experts like Smith warn of the role discrimination plays in disproportionately targeting and penalizing families of color.

“We live in a society that oversurveils people of color and has a long history of racism,” she said. “So it isn’t surprising that there is a disproportionate number of reports made where the families are part of a marginalized group.”

“Child welfare agencies work continuously to try and come up with screening and assessment tools that help to mitigate bias,” Smith continued, “but agencies are made up of human beings who are also members of communities where bias and racism exist.”

Smith believes engaging child welfare services in anti-racism training could help, as could boosting funding for these services.

The bigger challenge is addressing the systemic problems that often go hand in hand with child abuse and neglect, like poverty, lack of affordable child care and insufficient health care. Overincarceration and limited access to substance abuse treatment are also factors that often contribute to abuse and neglect.

“It is really hard to parent sufficiently when you are living in a car, have no money, and have a mental health condition,” said Smith.