OMAHA, Neb. (AP) — A jury has begun deliberating the case of a former medical resident accused of killing four people with ties to an Omaha medical school, including a young boy.

Anthony Garcia’s attorneys sought to poke holes in prosecutors’ case during nearly four hours of closing arguments Tuesday. Prosecutors pointed to credit card and cellphone records that put Garcia in and around Omaha on the day of two of the killings as part of their case.

Garcia is charged with stabbing to death the 11-year-old son of two doctors and the family’s housekeeper in 2008 and then killing another Omaha doctor and his wife in 2013. Prosecutors say Garcia was motivated by revenge against two of the doctors, who had him fired from the Creighton University medical school’s residency program in 2001.