An MS-13 member admitted to stabbing a teen to death in Brentwood two years ago in a brutal gang assault.

Elmer Alexander Lopez, a 20-year-old known as "Smiley," pleaded guilty to a racketeering charge Monday in connection with the slaying of 18-year-old Jose Pena in 2016.

Pena went missing in June of that year, and his skeletal remains were later uncovered at the Pilgrim State Psychiatric Center after an extensive search.

Prosecutors say at least five MS-13 members lured him into the woods in Brentwood and stabbed him to death.

In court, Lopez said he and other gang members killed Pena because they were told "he violated the rules."

Prior to the slaying, Lopez and other MS-13 members held meetings about whether to kill Pena, prosecutors say. They suspected he had cooperated with law enforcement and thought he might have been homosexual.

If he had been convicted at trial, Lopez would have faced a maximum of life in prison. Under a plea agreement, he faces a recommended punishment of 24 to 29 years at his sentencing in September.