The father of a first-grade girl who was killed in the Sandy Hook school shootings died in an apparent suicide Monday morning, Newtown Police confirmed.

Jeremy Richman, 49, was found dead at 7 a.m. inside Edmond Town Hall, where he had an office space, police told The Daily Beast. Authorities said the medical examiner’s office is still investigating the exact cause of death.

A neuropharmacologist, Richman co-founded the Avielle Foundation after his first-grade daughter, Avielle Richman, died in the 2012 massacre at Sandy Hook Elementary School in Newtown, Connecticut. The 6-year-old was among the 20 first-grade students and six administrators killed.

“This is a heartbreaking event for the Richman Family and the Newtown community as a whole, the police department’s prayers are with the Richman family right now, and we ask that the family be given privacy in this most difficult time,” Lt. Aaron Bahamonde said in a statement. “The death appears to be a suicide but police will not disclose the method or any other details of the death, only to state the death does not appear suspicious.”

In a later statement, Bahamonde said that some of the officers called to Monday’s scene also responded to the Sandy Hook shooting. The officers found a note next to Richman’s body, he added.

Richman and his wife, Jennifer Hensel, created the Avielle Foundation, which was dedicated to funding research into the neuroscience behind compassion and violence.

In a 2017 interview with NPR, Richman talked about the emptiness the couple felt after they lost their only child. “It was like a ghost limb syndrome, you know, where you keep thinking ‘Where’s Avielle? Do we need to pick her up?’” he said. “And every day you’d have this [realization] that I don’t have a child, and I don’t have to parent. That was just brutal.”

Richman and Hensel ultimately had two more children.

In another 2017 interview with the Rochester Democrat and Chronicle, Richman talked about how each new mass shooting roiled his emotions.

“Right after Newtown we had the Boston bombings, and then we’ve had Charleston, Orlando, and over a hundred school shootings, some of which make the national news and some don’t,” he said. “Every time this happens it breaks a heart and it chokes us up. To be honest, though, now it comes with a fair degree of frustration and anger, because things aren’t changing fast enough. I really get sick of ‘thoughts and prayers,’ and ‘our hearts go out.’ That’s not going to change anything. What I need to hear is: ‘My heart is broken, and my boots are on the ground to fix it.’”

According to the Hartford Courant, Richman–a trained scientist who also lectured at Yale University—had hosted an event at Town Hall earlier this month with author Brené Brown that several Sandy Hook families attended.

“He had such a clear purpose of what he wanted to do to honor his daughter,” one family member told the newspaper. “I’m just shocked. I’m sitting in my car right now crying. The foundation was doing really important work and was doing such good things.”

Richman and Hensel were among the parents who sued InfoWars’ Alex Jones for perpetuating the claim that the massacre was a hoax and that the children’s parents were “crisis actors.” Just last week, a judge ordered Jones to turn over a trove of emails and other documents to the families.

On Monday, Alex Jones called Richman’s death a “tragedy”—after blasting the media for bringing up the lawsuit.

“My thoughts and prayers go out to him and his family,” Jones said on his Infowars show.

Senator Richard Blumenthal (D-CT) expressed his condolences online, calling the passing of his “good friend... simply devastating.”

“My god. This is awful, horrible, devastating news. Jeremy was a good friend and an unceasing advocate for better research into the brain’s violence triggers,” Senator Chris Murphy (D-CT) tweeted Monday morning. “He was with me in my office two weeks ago, excited as could be about the Avielle Foundation’s latest amazing work.”

Richaman’s death comes just days after two survivors of the Parkland school shooting died from apparent suicides.

Sydney Aiello, whose mother said she suffered from survivor’s guilt after the mass shooting at Marjory Stoneman Douglas High School that left 17 dead, took her own life last Sunday, Coconut Creek police confirmed.

Aiello was close friends with Meadow Pollack, one of the victims from the Feb. 14, 2018 shooting.

On Saturday night, a second unnamed student survivor also died in an apparent suicide, the Coral Springs Police Department confirmed. The student was described as a male, 17-year-old sophomore at the high school.

“How many more kids have to be taken from us as a result of suicide for the government / school district to do anything?” Parkland survivor and March for Our Lives leader David Hogg tweeted Sunday morning.

If you or a loved one are struggling with suicidal thoughts, please reach out to the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).