"We certainly recognise the heartbreak that this is causing," he said in a phone interview. "It's a difficult situation that we're all dealing with here and it's a sad situation."
Following reports that Richman had died, government officials and friends expressed their grief and offered condolences to the family.
Newtown First Selectman Daniel Rosenthal said there were "no words to describe the tragic weight of today's news."
"Jeremy Richman was a loving husband, father and friend to many. I am proud to say he was my friend," Rosenthal said in a statement to the Hartford Courant. "I don't want to speculate as to why Jeremy took his life, except to say none of us can fathom the enormity of loss he carried with him after the death of his beautiful daughter, Avielle."
More than 2100km away in Parkland, Florida, two teenagers have died by apparent suicide in the past week in a town still grieving from the mass shooting at Marjory Stoneman Douglas High School.
Authorities have not drawn a connection to the apparent suicide in Newtown. One former student who died was apparently dealing with post-traumatic stress disorder from the shooting, but circumstances surrounding the second student's death remain unclear.
Richman's daughter Avielle and 19 of her classmates were killed on December 14, 2012, when a gunman opened fire at Sandy Hook Elementary School in Newtown, Connecticut. Soon after, Richman and Avielle's mother, Jennifer Hensel, both scientists, founded the Avielle Foundation: Preventing Violence & Building Compassion, a nonprofit that aims to prevent violence through brain research.
"When we were faced with this infinite heartbreak we decided we'd play to our strengths as scientists to see if we could answer the 'why' questions everyone had," Richman told ABC affiliate WTNH in 2017. "To see if we can understand what happens in the brain that leads to violence."
According to his biography on the organisation's website, Richman was a neuropharmacologist, studying how drugs influence the brain and nervous system.
Richman told WTNH that the pain never ended.
"Losing Avielle hurt then and hurts now," Richman told WTNH. "There's no words that really describe the loss and the feeling of emptiness and missing her profoundly that never goes away and is there every waking moment."
Police have not released details about his death.
WHERE TO GET HELP:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
OR IF YOU NEED TO TALK TO SOMEONE ELSE:
• 0800 543 354 (0800 LIFELINE) or free text 4357 (HELP) (available 24/7)
• https://www.lifeline.org.nz/services/suicide-crisis-helpline
• YOUTHLINE: 0800 376 633
• NEED TO TALK? Free call or text 1737 (available 24/7)
• KIDSLINE: 0800 543 754 (available 24/7)
• WHATSUP: 0800 942 8787 (1pm to 11pm)
• DEPRESSION HELPLINE: 0800 111 757 or TEXT 4202 (edited)