A Bloody scene greeted police when they arrived at the home in the Windsor Terry section of Brooklyn.
Inside, they found a 57-year-old woman with stab wounds to the eye and stomach and her 51-year-old husband stabbed in the neck.
The suspect is the couple's 31-year-old son, who is now in the hospital after witnesses say he threw himself in front of an on coming train.
Neighbors say the suspect's name is Ryan Devaney and they he has a long history of drug and mental problems.
Detectives are not saying what set off the attack, but say after stabbing his parents the suspect ran to the nearby subway stop at the end of the block.
Neighbors say a doctor who lives on the block spotted the suspect covered in blood then watched in horror as he jumped in front of on coming train.
Amazingly, the man survived and was rushed to Lutheran Medical Center.