The Brooklyn man accused of killing four people in a 28-hour stabbing spree entered a guilty plea in court today. Police say Maksim Gelman killed four people and injured four others back on Feb. 11 after an argument over whether he could use his mother's car. Authorities say Gelman first killed his stepfather in Sheephead Bay, then killed a girl he knew and her mother, plus an innocent bystander whom he ran over with a stolen car. Gelman was arrested in Manhattan after slashing someone on the 1 train.BK stabbing spree suspect indicted on multiple chargesPolice arrest suspect in deadly Sheepshead Bay rampageVigil held for victims of BK stabbing spree