He's also charged with fatally shooting his 20-year-old cousin, John.
Defense attorneys did not call on any other witnesses today, but show the taped interview Prince had with investigators the morning of the murders.
The incident happened at Prince's home at #2 Rene Circle on August 30, 2009.
Police say Prince first shot his girlfriend, who survived with a shoulder wound, then fatally shot his cousin and fatally beat his 23-month-old son Trebian in the head with a gun and a claw hammer.
This morning in the 30th District Court, defense attorneys showed the jury the recorded interview Prince had with Wichita Falls police detectives the morning of the crimes.
The defendant closed his eyes and plugged his ears while the video was shown.
During the 25 minute video, Prince first denied to talk to officers.
Investigators then brought Prince's father in the interview room, who asked his son to tell authorities what happened.
Prince repeatedly yelled, "Where is my son?"
Prince also asked officers why he had blood all over him and whose blood it was.
Closing arguments are set to begin tomorrow morning at 8:30.
Judge Brotherton will prepare the formal charge, then the jury will deliberate on guilt or innocence following those arguments.
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