PHOENIX (AZFamily) — A man is set to spend two decades behind bars for killing a Phoenix teen girl over 20 years ago.
On Friday, 39-year-old Sergio Francisco Reyes was sentenced to 20 years in prison for the murder of 15-year-old Elena Lasswell.
A year after being extradited to the U.S. from Mexico, Sergio Reyes has been sentenced to prison for the 2004 murder of 15-year-old Elena Lasswell in Phoenix.(Phoenix Police Dept./Maricopa County Sheriff’s Office)
On the evening of July 10, 2004, Lasswell’s brother and his friends found the girl dead in her bedroom at a home near 23rd Avenue and Thomas Road. An autopsy revealed she died from strangulation and blunt force trauma to her head. The girl had also been sexually assaulted.
Witnesses reported seeing Lasswell and a teen boy between 16 and 19 go into her bedroom and shut the door the night before, July 9. That was the last time she was seen alive.
Police followed leads, but the case went cold for years.
Then, in 2012, Phoenix Police cold case detectives used new techniques to create a DNA profile that matched a name in the system, Reyes, who would have been 17 at the time of the murder. Familial DNA was then used to confirm Reyes as the lead suspect the following year.
He was indicted by a grand jury in 2014, but Reyes lived in Mexico at the time. An extradition process was started, and it took investigators another 10 years to find and arrest him.
Reyes was extradited to Maricopa County and arrested by Phoenix police last July, 20 years to the day of Lasswell’s murder. He was booked into jail for first-degree murder, sexual assault and kidnapping.
As part of a deal, Reyes pleaded guilty in August to a lesser charge of second-degree murder. The other charges were dismissed.
“This case highlights the tireless efforts of Phoenix Police detectives and MCAO prosecutors who never gave up in the pursuit of justice for Elena and her family,” Maricopa County Attorney Rachel Mitchell said in a news release. “This defendant tried to run and hide, but in Maricopa County, the truth will catch up to you and so will law enforcement.”
See a spelling or grammatical error in our story? Please click here to report it.
Do you have a photo or video of a breaking news story? Send it to us here with a brief description.
Copyright 2025 KTVK/KPHO. All rights reserved.