Murdock, 25, was found about 8:30 a.m. Monday in his car parked in front of Middleton High School, Tampa police said in a statement. The statement said he was injured by an apparent self-inflicted gunshot wound.
He was taken to a hospital and declared dead about 2 hours later.
Murdock hadn't reported to Titans training camp this year because what the team termed "personal reasons." He was signed by Tennessee last year as an undrafted free agent but missed the entire season due to an Achilles injury.
"We are shocked and saddened to hear of O.J. Murdock's death this morning," the Titans said in a statement. "In his brief time here, a number of our players, coaches and staff had grown close to O.J., and this is a difficult time for them. He spent the last year battling back from an Achilles injury as he prepared for this year's training camp. Our thoughts and prayers are with his family and friends as they try to cope with this tragedy."
Murdock was selected the Tampa Tribune's Male Athlete of the Year in 2005 after winning two state championships in track and catching 57 passes for 927 yards and 11 touchdowns as a senior, the newspaper said.