WASHINGTON — From school shootings to synagogue bombings, leading AI chatbots helped researchers plot violent attacks, according to a study published Wednesday that highlighted the technology’s potential for real-world harm.

Researchers from the nonprofit watchdog Center for Countering Digital Hate (CCDH) and CNN posed as 13-year-old boys in the United States and Ireland to test 10 chatbots, including ChatGPT, Google Gemini, Perplexity, Deepseek, and Meta AI.

Testing showed that eight of those chatbots assisted the make-believe attackers in over half the responses, providing advice on “locations to target” and “weapons to use” in an attack, the study said.

The chatbots, it added, had become a “powerful accelerant for harm.”

“Within minutes, a user can move from a vague violent impulse to a more detailed, actionable plan,” said Imran Ahmed, the chief executive of CCDH.

“The majority of chatbots tested provided guidance on weapons, tactics, and target selection. These requests should have prompted an immediate and total refusal.”

Perplexity and Meta AI were found to be the “least safe,” assisting the researchers in most responses while only Snapchat’s My AI and Anthropic’s Claude refused to help them in over half the responses.

In one chilling example, DeepSeek, a Chinese AI model, concluded its advice on weapon selection with the phrase: “Happy (and safe) shooting!”

In another, Gemini instructed a user discussing synagogue attacks that “metal shrapnel is typically more lethal.”

Researchers found Character.AI also “actively” encouraged violent attacks, including suggestions that the person asking questions “use a gun” on a health insurance CEO and physically assault a politician he disliked.