A Brooklyn man was arrested at a Sandy Hook massacre charity event in Connecticut for accosting a victim’s family — and yelling that the shooting was a hoax, cops said on Tuesday.

Matthew Mills, 32 — an infamous Sandy Hook “truther” — approached the family of slain teacher Victoria Soto at the Vicki Soto 5K Run in Stratford on Saturday and claimed that the 2012 shootings in Newtown, Conn., which killed 20 youngsters and six educators at an elementary school, “never happened.”

Mills then ran from cops, but was caught soon after.