Matti had reportedly been drinking when he disappeared.
His friends spent six hours looking for him before calling the Carroll County Sheriff's Department around 11:30 p.m.
A search of the shoreline was then conducted by members of the sheriff's department and the Indiana Department of Natural Resources. On Monday, the search expanded to include divers, sonar, search dogs and a fixed-wing airplane from the Indiana State Police.
Matti's body was recovered Tuesday.
WLFI.com reported, "Matti's body was recovered Tuesday morning on Lake Freeman. DNR officers said they found Matti's body 20 yards from the dock of the home where he'd been staying with friends on Lake Freeman."
Carroll County Coroner Jay Cree later said the preliminary cause of death was respiratory arrest and asphyxia due to drowning. The manner of death is being called an accident. Toxicology results are still pending.
About Sean Matti
Head Coach Danny Hope told CBSSports.com, "Sean Matti was a coach's dream. He was a very special teammate and I really believe he represented what we're all about. He had an unbelievable amount of pride and he loved Purdue. We are sure going to miss him."
According to Rivals.com, "Matti, a former high school star from Shoreview, Minn., was on track to finish his Boilermaker career this fall as a fifth-year senior after initially walking on in 2007, though he had yet to see the field in his first four years."
On Sept. 3, Matti's fellow Boilermakers had a moment of silence in his honor prior to their season opening game against Middle Tennessee State. They also dedicated their season in his memory.
On July 6, 2011, a memorial service was held at Saint Thomas Aquinas Center in West Lafayette, Ind.
Name/age: Sean Alan Matti, 22
Date of birth: 9/18/88
Hometown: Shoreview, MN
College: Purdue University
Major: Double major in organizational leadership and supervision major and industrial technology
Last Seen: 7/3/11, 5 p.m.
Physical Description: 6'0," 233 lbs.
Investigating Agency: Carroll County Sheriff's Department
Hinton, Matt. (2011, July 05). Body of missing Purdue running back found in Indiana lake. ABC News Rivals.com.
Retrieved June 28, 2012 from http://rivals.yahoo.com/ncaa/football/blog/dr_saturday/post/Update-Body-of-missing-Purdue-running-back-foun?urn=ncaaf-wp3281
Staff Article. (Undated). Sean Matti profile. CBSSports.com. Retrieved June 18, 2012 from http://www.purduesports.com/sports/m-footbl/mtt/matti_sean00.html
Staff Reports. (2011, July 7). Boilers gather to remember Sean Matti. PurdueSports.com. Retrieved June 18, 2012 from http://www.lafayette-online.com/purdue-news/2011/07/boilers-remember-sean-matti