Christopher Lane, a 22-year-old Australian baseball player, was shot and killed August 16, 2013 while jogging in Duncan, Okla. Police say three "bored" teenagers who decided to kill someone for fun are responsible.
A 17-year-old in the group has reportedly given a detailed confession to police.
That teen and the others - ages 15 and 16 - remain in custody, and police say the district attorney is expected to file first-degree murder charges.
Lane attended East Central University in Ada, about 85 miles west of Duncan. He started 14 games as catcher last year and was entering his senior year.
One of the suspect's mothers told CBS affiliate KWTV in Oklahoma City her son and his friends were in a "wannabe gang." Police told KWTV the suspects may have killed an animal prior to shooting Lane, and that they planned on killing more people.