Man bites off part of cop’s middle finger

HE BIT OFF all he could chew.

An unhinged man who chomped off a piece of a cop’s middle finger at a Brooklyn stationhouse swallowed the digit before cops could retrieve it, authorities said.

Ainsley Johnson, 34, gulped down the fingertip during a fight with a cop who was escorting him into a jail cell at the 69th Precinct in Canarsie about 6 p.m. Friday, cops said.

About an hour earlier, cops arrested Johnson on E. 99th St. after he wigged out on a 46-year-old resident, breaking the windows of the man’s 2003 BMW and crushing his victim’s mailbox with a cement planter.

Cops took Johnson in on criminal mischief charges.

While at the stationhouse, Johnson resisted as a 24-year-old cop who tried to re-handcuff him — and the two tussled, falling onto the floor. That’s when things turned feral. Johnson bit off the cop’s finger “from nail to tip,” police sources said.

Medics rushed the cop, who has been on the force for two years, to Kings County Hospital.