An 18-year-old Maryville College football player was charged Wednesday with first-degree murder in the shooting death of a high school cheerleader in Knoxville, Tenn. Acquaintances said the two had been a couple, but had broken up recently. On Tuesday, after the shooting, the alleged killer tweeted: "That's my beautiful Emma. Rest easy now sweetheart. 1 Corinthians 13:8. Be sure to remind God about our verse. I love you. Forever and always."

William Riley Gaul, 18, is charged in the death of 16-year-old Emma Jean Walker, who was fatally shot in her bedroom while she slept, according to the Knox County Sheriff's Office. She was a junior student at Central High School. Her body was discovered about 6:30 a.m. Monday. It appeared she had been shot from outside the home, authorities said.

Deputies arrested Gaul, and drove him early Wednesday to the City County Building for processing, reports USA Today. There were no news updates yet on how Gaul accessed a loaded weapon.

The romantic relationship between the two had ended in recent weeks, although Gaul refused to accept the breakup, the victim's aunt said.

"She had chosen to move on," Jenny Weldon, Walker's aunt, said Wednesday, reports The Tennessean. "He refused to accept it. He chose not to accept her wishes."

Weldon described her niece as a "beautiful soul" who was anxious to graduate high school and begin studying toward her dream of becoming a neonatal nurse. "Her heart was in service. She was born to be a helper."

After the shooting, detectives placed Gaul under surveillance, concerned that he was preparing to destroy evidence connected to the killing, according to the Sheriff's Office. Gaul, of Knoxville, remained jailed Wednesday in lieu of $750,000 bond.

A preliminary hearing about this case has been scheduled Dec. 2 in Knox County General Sessions Court.

Gaul, a 2016 Central High graduate who played on the school's football team, was listed as a freshman wide receiver on the Maryville College roster. Maryville College spokeswoman Chloe Kennedy said Wednesday afternoon Gaul has been dismissed from the football team. Maryville College maintains an affiliation with the U.S. Presbyterian Church.

Gaul posted several tweets professing his love for Walker, including a lengthy tribute that appeared online several hours after she was found dead.

"Living everyday through Emma Walker. I love you beautiful and I know you're in a better place now," Gaul's Twitter bio reads.

"Our student was a wonderful young lady, a cheerleader and honor student with a promising future, whose life was cut too short, too soon," Central High School Principal Michael Reynolds said in a statement Wednesday. "At this time, our hearts and thoughts and prayers are with the family as they go through this grieving process. We thank everyone in our community for their tremendous support."