Maksim Gelman is accused of first stabbing his stepfather, Aleksander Kuznetsov "numerous" times early Friday morning, according to the New York City Police Department.
Just 11 hours later, Gelman allegedly drove a few blocks away and stabbed his 20-year-old girlfriend Yelena Bulchenko, and her mother, 56-year-old Anna Bulchenko.
All three were found dead by police.
Gelman then fled in a stolen Lexus, police said. He then dumped that car and carjacked a Pontiac, stabbing the driver, who was later reported in stable condition, reportsThe New York Times. In the second car, Gelman allegedly ran down a pedestrian, who died later at a hospital.
Early Saturday morning, a subway rider recognized Gelman on the No. 3 subway train near Times Square, and alerted authorities, the New York Post reports.
Gelman then allegedly attacked a 40-year-old passenger aboard the train, stabbing him in the neck.
The passenger survived, and police later caught Gelman after he fled down a subway tunnel, the Post reports.