Rare illness had plagued slain teach

A DOWN-AND-OUT teacher murdered in a homeless shelter last year reportedly suffered from a rare illness that made him make poor decisions with his money.

Deven Black, 62, was killed Jan. 27, 2016, in a homeless shelter near 124th St. and Lexington Ave. by fellow resident Anthony White, 21. White later took his own life and was found floating in the Hudson River.

A year after Black’s murder, doctors have concluded the depression that drove him into the shelter was actually frontotemporal dementia, The Associated Press reported Monday.

Tests confirmed that Black, who also had been an award-winning librarian working in the city’s public schools, suffered from the illness, based on microscopic specks of a protein linked to the disease found on his brain.

Frontotemporal dementia affects more than 50,000 people nationwide. The “behavioral variant” can cause people to make impulsive decisions and behave in bizarre ways.

The symptoms are often wrongly assumed to be depression, bipolar disorder or simply a midlife crisis. A 42-YEAR-OLD man busted for killing another man in the victim’s Brooklyn apartment claims he carried out the stabbing after nearly getting injected with a needle when he tried to leave the home, police sources said Monday.

The suspect, David Keegan Riotto-Haigh of Philadelphia, met James Johnson, 41, in a club last week and spent the weekend at his apartment on Fleet Walk, in the Ingersoll Houses in Fort Greene.

At about 6 a.m. Sunday, a 911 caller — believed to be the suspect — said he had just killed someone who wouldn’t let him leave the apartment, sources said.

Police found Johnson with a knife sticking out of his chest. Riotto-Haigh, who appeared high on drugs, had cuts on his hand and a broken finger, sources said.

He told police the victim tried to inject a needle into his arm, at which point the killer grabbed a knife and stabbed him several times, sources said.

He has not yet been charged in the case.