Authorities in Florida say a 20-year-old man called 911 Thursday evening to confess killing his 18-year-old girlfriend.

According to Naples Daily News, Santiago Burbano was arrested shortly after that call and is expected to face charges including second-degree murder in connection with Rubi de los Angeles Velasco’s death.

Police believe Burbano was at the victim’s apartment in Naples when his mother received a phone call from another relative who suggested she should check on him.

The woman reportedly arrived at the apartment a short time later and found her son locked in his bedroom.

He allegedly confessed to the murder at that point.

“Mommy, mommy, I killed Rubi,” he allegedly said.

His mother said she was finally able to talk the suspect into letting her in the room, she told police. Upon entering, she said she saw Burbano seated at a desk with a rifle.

He allegedly had the gun pointed to his head until his mother convinced him to remove it. At that point, she reportedly called the sheriff’s office to turn in her son.

Authorities reported finding Velasco’s body inside the home with lacerations on her neck.

The victim’s family has set up on online fundraiser in an effort to help with her final expenses.

“Rubi Velasco was a 18 year old happy girl, recently graduated from high school, who moved to the United State with her mom From Venezuela for a better Life,” the GoFundMe post reads.

Her family said that “her beautiful life was over” because of an ex-boyfriend.

“Words cannot describe how her family and friends feel about this horrible news,” the post concluded.

[Featured image: Santiago Burbano/Collier County Sheriff’s Office, Rubi Velasco/GoFundMe]