Alan Hausman paused mid-sentence during the phone call, then said he is still dogged by "survivor's remorse." 

Hausman said he can clearly remember trying to drive up a road to get to the Tree of Life synagogue in Pittsburgh after he was alerted to a shooting. But the road was impassable. The memories of the aftermath are indelible. 

"Every time I see another attack, it's like someone picked the scab off of my wound," said Hausman, who is the president of the synagogue's board of directors. He was not attending the synagogue on the day of the October 2018 shooting spree that killed 11 people.

The massacre resulted in 63 counts including hate crime charges, resulting in the conviction and a death sentence against the gunman.    

Hausman, who is an emergency management official in Pittsburgh, said the Tree of Life now has armed security, as do other religious institutions and organizations in the city and region. The houses of worship have installed new alarm systems, and have roving security guards in parking lots, to deter future threats, he said.

According to FBI data and Justice Department officials who spoke with CBS News, the Tree of Life tragedy didn't slow the targeting of religious institutions, but was an early warning of the recent wave of planned attacks.

FBI crime reports reviewed by CBS News show assaults or attacks against people at churches, synagogues, temples and mosques surged nearly 100% between 2021 and 2023.     

In an interview with CBS News, assistant Attorney General for Civil Rights Harmeet Dhillon referenced a growing stack on her desk of criminal cases that allege the targeting of religious centers.   

"I think it's a form of terrorism, because attacks on churches are meant to terrorize people," Dhillon said. "And they're meant to deter people from going there. And so it makes everyone feel unsafe."

On June 18, Justice Department prosecutors secured a 25-year prison term in the case of Rui Zhang of Virginia. Zhang was convicted of targeting a Haymarket, Virginia, church for an attack. Prosecutors alleged Zhang had written a manifesto, and that he was inside a Sunday service at the church with a semiautomatic handgun, two magazines of ammunition, and two knives. He allegedly had additional ammunition, knives, and a canister of bear spray in his nearby car. 

In April, the Justice Department also secured a conviction of an Arizona man of targeting a series of churches. According to investigators, Zimnako Saleh "traveled to four Christian churches in Arizona, California, and Colorado, wearing black backpacks. At two of those churches, Salah planted those backpacks, placing congregants in fear that they contained bombs. 

At the other two churches, Salah was confronted by security before he got the chance to plant those backpacks. Photos of backpacks and movements from the day of the attempted attack inside the churches were included in charging documents.

Dhillon said civil rights investigators have marshalled a more focused effort to combat the targeting of houses of worship.  

"We want to shut that threat down by making sure that no one is feeling like churches, houses of worship, people of faith are soft targets in the United States," Dhillon said. "That is why it's a priority."

The increasing wave of threats against religious centers is – at least partly – driven by emerging white nationalism or the targeting of minority groups or churches that are welcoming to LGBTQ communities, according to the Southern Poverty Law Center, a liberal-leaning nonprofit organization which focuses on civil rights issues and combating hate crimes.

"About one in 10 of the attacks that we documented in the first six months of 2024 were also focused on 'welcoming' religious communities," said R.G. Cravens, an SPLC researcher. 

"We have seen an uptick in synagogues being targeted for similar things like vandalism, graffiti and harassment  since the October 7th (attacks) in Israel," Cravens added. "And those come in a lot of forms that often do indicate the hard right white nationalist and white supremacist groups are involved."

Dhillon directed CBS News to several other recent cases under investigation by the Justice Department. In February, Kevin Colantonio, 36, of Rhode Island pleaded guilty to a federal criminal charge for setting multiple fires around the exterior of a predominantly black church in North Providence.

The federal criminal cases yield the possibility of lengthy prison terms. Zhang's prison term runs through the year 2050.    

Dhillon said the Justice Department's new leadership has an urgency in tackling these cases, pointing to hate crime charges filed against a man who allegedly used Molotov cocktails to attack peaceful marchers in Boulder, Colorado, on June 1.

"We were all over it. And we filed what has been described to me as the fastest hate crime criminal complaint in recent history," Dhillon said. "It is important for the community being targeted to feel and see that the United States is taking these crimes with the utmost seriousness."

The Justice Department is preparing for an August court hearing in the case of Elias Rodriguez, who is accused of targeting and murdering two Israeli embassy officials in Washington, D.C. last month.   

Rodriguez allegedly shot and killed the victims — a couple about to become engaged, according to Yechiel Leiter, Israel's ambassador to the U.S. — as they were leaving the museum, which is located in the heart of the U.S. capital. According to police and video from the scene, he shouted "free, free Palestine" as he was being taken into custody.     

Within 24 hours, the Justice Department announced that the case was being investigated as a potential hate crime.  Rodriguez is being held in pretrial detention.