A Brooklyn man is suing his brother for allegedly killing their mother.

Richard Cohen, 34, was charged with murder for allegedly stabbing Ann Cohen 40 times in her Midwood home in August 2012.

Sibling Michael Cohen lived with Ann “his entire life” and “had a very close and loving relationship,” according to the Brooklyn Supreme Court lawsuit he filed last week.

Michael Cohen is suing for “an amount in excess of millions of dollars.”

Richard Cohen is being held without bail at Rikers Island.