About an hour later, they asked to go home. Their deliberations are scheduled to resume Wednesday.
Mix is charged with two counts of obstruction of justice. Prosecutors claim the 52-year-old resident of Katy, Texas, deleted text messages to and from a supervisor and a BP contractor to conceal them from a grand jury.
The jury has deliberated for more than eight hours since closing arguments Monday by Justice Department prosecutors and a lawyer for Kurt Mix, who is charged with two counts of obstruction of justice.
Prosecutors say Mix, 52, of Katy, Texas, deleted two strings of text messages from his cellular phone - one with a supervisor and another with a BP contractor - to conceal them from a grand jury probing the nation's worst offshore oil spill.
Mix's lawyers said he didn't try to hide anything from the grand jury and preserved other records with the same information contained in the deleted texts.
The indictment also says Mix deleted two voicemails from the same two people. He didn't testify at his trial, which started two weeks ago. Each count of obstruction of justice carries a maximum sentence of 20 years in prison and a $250,000 fine.
Mix is one of four current or former BP employees charged with crimes related to the spill. His case was the first to be tried.
The April 20, 2010, blowout of BP's Macondo well triggered an explosion that killed 11 workers on the Deepwater Horizon drilling rig. Millions of gallons of crude spewed into the Gulf after the blowout.
Mix was on a team of experts who tried in vain to stop the flow of oil using a technique called "top kill." He had access to internal data about how much crude was flowing from the blown-out well.
On May 26, 2010, the day that top kill began, Mix estimated in a text to a supervisor that more than 630,000 gallons of oil per day were spilling - three times BP's public estimate of 210,000 gallons daily and a rate far greater than what top kill could handle.
That text was in a string of messages that Mix exchanged with his supervisor, Jonathan Sprague, before deleting it in October 2010. Investigators couldn't recover 17 of the messages in the string.