Police on Wednesday were interviewing Washington State quarterback Tyler Hilinski's friends and people who knew him to try to learn why he apparently took his life. Police Chief Gary Jenkins said officers have no apparent motive for the death of the 21-year-old athlete, who was found dead in his Pullman, Washington, apartment on Tuesday along with a rifle and a suicide note. "The missing piece here is why," Jenkins said. "Most of our investigation will be conducting interviews." Jenkins declined to reveal the contents of the suicide note. Hilinski's family in California issued a statement saying they were in "complete shock and disarray" over his death. "Tyler was the kid that put a smile on everybody's face when they were down, especially his family," the statement said. "We will mourn the loss of Tyler for some time but celebrate the way he lived his life every day." A makeshift memorial for Hilinski has sprouted near the football stadium on the Pullman campus, next to a bronze statue of the team's cougar mascot. The memorial included flowers and balloons. Social media was also filled with comments about Hilinski. Former Washington State quarterback Ryan Leaf tweeted that he could not stop crying when he heard the news. "Every human life is precious," Leaf said, adding he wished he could have told Hilinski: "I'm just like you & I've been here & there is hope." Hilinski backed up Luke Falk this season and was the presumptive starter heading into his junior year. He appeared in eight games during his sophomore season, throwing for 1,176 yards and seven touchdowns. The most memorable outing of his career came in the second week of the season, when he came off the bench to rally Washington State from a 21-point deficit in the fourth quarter to beat Boise State in triple overtime. Hilinski was carried off the field after the victory. His only start came in a loss to Michigan State in the Holiday Bowl in December, the final game of the season for the Cougars. Hilinski was from Claremont, California, and went to high school in nearby Upland. He arrived on campus in 2015 and redshirted before appearing in four games in 2016. ___ For more AP college football coverage: http://collegefootball.ap.org and http://twitter.com/AP_Top25