This is a tough one, so I'll just tell you who it is. If you subtract the beard, hair, and about 65 pounds from this guy, but kept the expressive eyebrows and sort of wild expression, you might be able to guess that this is John Turturro's brother.
According to the Post, Ralph Turturro has been causing all kinds of problems for his Hell's Kitchen neighbors on West 46th--they've called the cops on him 5 times since August:
John Turturro's troubled older brother has them living in fear -- threatening to kill them and his caretakers, screaming at all hours of the night, and leering at female residents.
"He's explosive," said Deborah Miller. She said she had to call the cops Aug. 30 because Ralph, who was locked out of his own place, was trying to get into her apartment around 1 a.m. "Get me a key, bitch!" he screamed.
The more famous Turturro's Wikipedia entry says that his older brother Ralph is a middle school art teacher, but the Post says he's an unemployed artist who has "caretakers" with him all the time, which I'm guessing means he lost that teaching job. Neighbors say they hear him screaming and throwing furniture around the apartment.
While the older Turturro [UPDATE: it turns out the artist is John Turturro's cousin, not his brother, and is not mentally ill] may have mental problems, his art isn't bad. I found a website that appears to be his featuring a lot of his abstract art. I'm no expert on this, but some of it looks really good (I like this one from 2002.) The "recent works" are from 2003 and earlier, so maybe his creativity has suffered lately. His artist's statement is an interesting take on abstraction, subjectivity, and discipline, so it seems like he had his shit together at one point.
In an interview from 2 years ago, Ralph Turturro says he comes from a family of artists, though "the rest of my family that aren't actors never talk to each other because of one emotional thing or another." Maybe that means he's still in touch with John and Aida who can help get him away from his neighbors.
UPDATE: It turns out the mentally ill Ralph Turturro, John's brother, is not the same person as Ralph Turturro the artist. The professional artist is John's cousin, and is not mentally ill. See the comments for more anecdotes from one of the neighbors dealing with the unwell Ralph's outbursts.