Sean Burton's attorney made the request during a hearing Tuesday in Delaware County Court.
Burton, of Newark, Del., was arrested June 21 in Springfield after police say he fled from an SUV carrying James Stropas' dead body.
During Tuesday's hearing an officer testified that Burton said Stropas had come at him with a knife.
Defense attorney Mark Much says the medical records could help show Burton was justified in stabbing Stropas. The attorney says Stropas claimed to have post-traumatic stress disorder following two tours of duty in Iraq.
Judge Barry Dozor says he will rule on the request later.
Information from: Delaware County Daily Times