A bloody fight broke out Tuesday night in a Brooklyn Heights public library after a homeless man there became enraged after seeing another man watching porn.

 

According to police, the homeless man, Ralph Neptune, was on the second floor of the Brooklyn Heights public library at about 7:30 p.m. Tuesday when he saw another man, 52, watching porn on a computer there.

 

He confronted the man, said Police Commissioner Ray Kelly, and the man looking at porn picked up a chair and hit him with it.

 

That's when Neptune pulled out a knife, and stabbed the porn-viewer in the chest, said police.

 

The victim, who was still conscious and talking after the attack, was brought out of the library in a wheelchair. He was treated at Bellevue Hospital for non-life-threatening injuries.

 

Neptune was charged with assault.