Prosecutors in the American Sniper trial played Eddie Ray Routh's videotaped confession in court on Monday.
Routh is on trial for the capital murder of former Navy SEAL sniper Chris Kyle and his friend and fellow veteran Chad Littlefield.
Routh is seen in the video sitting in a Lancaster police department room handcuffed and at times with his face down on a table.
Routh admits in the footage he shot the two men. Eventually, Routh said he knows what he did was wrong and would apologize to the family if he could. Knowing his actions were wrong is a key admission to prosecutors trying to prove Routh was sane.
An investigator also testified that Kyle and Littlefield were repeatedly shot, indicating the shooter was "someone very violent."
Texas Ranger Danny Briley testified the Feb. 2013 shootings were intentional because Kyle was shot six times and his friend, Chad Littlefield, seven times.
Defense attorneys have said Routh, a former Marine who was taking anti-psychotic medication, was insane when Kyle and Littlefield took him to a shooting range to provide support and camaraderie.
They're trying to convince jurors to find Routh not guilty by reason of insanity. Prosecutors say he knew his actions were wrong and should be convicted of capital murder.
Testimony will resume in the trial on Tuesday morning in Erath County.
The Associated Press contributed to this report.