DALLAS (AP/CBSDFW.COM) – A Dallas jury has sentenced a man to life in prison after his conviction in the fatal shooting of a police officer who was serving a warrant.

Charles Payne was convicted Friday of murder instead of capital murder in the 2009 death of Sr. Cpl. Norm Smith. Capital murder could have resulted in a death sentence.

When 29-year-old Payne was sentenced on Monday, he showed no visible emotion, though his supporters left the courtroom in tears.

Officers admitted using a fake name when knocking, but insisted they identified themselves as police before shots were fired. Payne had testified he thought he was being robbed and did not know that the people outside the door of his apartment were police, looking for another man inside the unit.

Smith, who was 43, was killed almost instantly when Payne fired through the door, striking him near his left eye.

But the jury found he did not act with sudden passion, a finding that could have resulted in a sentence of two to 20 years.

Jurors reportedly told prosecutors after the trial that some of them struggled with determining whether Payne knew who he was firing at through the door.

Dallas District Attorney Craig Watkins said that he was “satisfied with what the jury decided,” and said it “sent a message to the citizens of Dallas County you just don’t shoot at the police.”

(© Copyright 2011 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)