A new report on school safety from the American Civil Liberties Union confirms what leaders in Pennsylvania districts with large numbers of disadvantaged kids have been seeing for years —– too many students are getting arrested instead of receiving mental-health aid to head off violence before it starts.

“For a lot of our children — especially in urban areas with this violence, in Chester and Philly… the mental trauma piece is missing,” said Anthony Johnson, president of the Chester Upland school board, about the ACLU’s finding that many U.S. schools lack counselors, psychologists, or nurses, even as armed policing increases.

In Johnson’s Delaware County district — dogged for years by low funding and a high poverty rate — administrators are looking to place more mental-health providers in schools. “We probably need on-site people every day," he added.

The ACLU study — Cops and No Counselors: How the Lack of School Mental Health Staff Is Harming Students — found there are 1.7 million American children attending schools that have police officers but no counselors, part of a trend of criminalizing youth behavior while not offering enough early intervention.

The civil-liberties group also said some of the nationwide problems it uncovered are even more pronounced in Pennsylvania. In particular, the ACLU found the state has the third-highest student arrest rate in the nation — a number that spiked by 24 percent in just two years — and the second-highest for black and Hispanic kids. It found an African American girl is five times more likely than a white girl to get arrested in a Pennsylvania school.

“The shortage of counselors, nurses, social workers, and school psychologists is a significant problem in Pennsylvania,” said Harold Jordan, senior policy advocate for the ACLU’s Pennsylvania chapter. He said filling school hallways with armed security officers “is a misguided notion” that would not prevent school shootings.

Jordan said the number of Pennsylvania children in schools with police but no counselors is about 30,000, relatively small compared with other states. More alarming, he said, were high rates of student arrests. In Allegheny County, for example, school-based arrests are the main factor sending African American girls into the juvenile justice system.

The argument for more mental-health professionals, Jordan said, is that “what you can do is create situations where adults with professional skills get to know kids well enough to know about... conflicts that have potential to cause school violence and intervene.”

Heather Marcus, a counselor at Philadelphia’s Masterman School and organizer of Philadelphia School Counselors United, said the ACLU report reinforced what staff see inside city schools daily.

“When we see problematic behaviors, there’s something underneath that — and school counselors get to what’s underneath,” Marcus said. “Adding school counselors is a way to stop the school-to-prison pipeline, instead of criminalizing our youth.” She said the situation in Philadelphia has improved since the depths of the fiscal crisis earlier this decade, when some city schools lacked nurses or guidance counselors, but “we could be doing so much more.”

The ACLU report comes during a national debate over school safety that has accelerated since a rash of school shootings — most notably the Parkland, Fla., high school massacre that claimed 17 lives last winter.

Many schools have tightened security measures — adding more metal detectors or cameras, hiring armed guards, or increasing visits by municipal police. Last September, for example, Pennsylvania Gov. Tom Wolf ordered state troopers to visit schools and college campuses once every shift in the 1,300 municipalities where they’re the primary police force.

But the ACLU report argues that police are largely trained to make arrests and not deal with the complicated traumas faced by young people, especially in lower-income communities. It found 3.5 times as many arrests in schools with police as in those without them — disproportionately targeting nonwhites and the disabled.

At the same time, the ACLU study detailed a pronounced shortage of counselors, nurses, psychologists, or social workers who could serve as the front line of defense on problems like the rising suicide rate, which from 2006-16 skyrocketed by 70 percent among children aged 10 to 17.

In Chester Upland, school board president Johnson noted the district has metal detectors in schools, “yet our problem is violence in the community.” He said he would like to see more kids getting help for the trauma they experience on the outside, “and get with the parents and start some therapy.”