In the video, Hernandez is shown carrying what appears to be a gun.
“That, ladies and gentlemen, is a Glock,” Assistant District Attorney Patrick Bomberg told jurors.
Hernandez, had tampered with the cameras but investigators were able to retrieve photographs, prosecutors previously claimed. Those images, they said, were recovered from 14 surveillance cameras in Hernandez's $1.2 million home.
Hernandez has pleaded not guilty to murdering Lloyd. His attorney, Michael Fee, insisted during opening arguments today that his client lacked intent to murder, and added that Hernandez did not turn off or tamper with the footage from his home surveillance system.
"The evidence will show that if Aaron Hernandez wanted to destroy the recordings on that video system, he could have," Fee said. "But he did not, because he had no reason to."
ABC News' Aaron Katersky and Michele McPhee contributed to this report.