Frank Deleon Jr., 17, was arrested on Monday night and has been charged with murder, according to Houston police.
The shooting occurred around 9:30 p.m. January 11 in the 15400 block of Park Manor Street.
According to police, Deleon was in a romantic relationship with Alvarez and another female. When Alvarez learned about the other relationship, she met Deleon at a nearby park, where he shot her, police say.
Her mother told FOX 26 last week that Alvarez said she was going out to walk her dog, and she didn’t realize the girl had planned to meet someone.
Alvarez never came back. Her family knew something was wrong and ran outside when the dog returned to the house by himself.
Down the street, the family found Alvarez shot multiple times.
Police say detectives worked closely with the community to track down witnesses and leads.
"HPD expresses its heartfelt condolences to Ms. Alvarez’s family and looks forward to following this case through the courts as we seek justice on her behalf," HPD said in a statement. "We ask that the public continues to pray for the family and respects their privacy."