A man who shot and killed his stepmother and half-brother in Imperial Beach pleaded guilty in Chula Vista Superior Court this week to two counts of murder. Marco Antonio Valadez Jr., 50, admitted on Monday to the Dec. 4, 2021, slayings of Raquel Pitsenberger, 55, and her 36-year-old son, Marco “Tony” Valadez Jr. Sheriff’s deputies found the victims inside a home on Fern Avenue that afternoon. Pitsenberger died at the scene, while her son died at a hospital. Valadez was arrested in Mexico and extradited to the United States less than two weeks after the deadly shootings. The District Attorney’s Office said in a prior statement that the killings stemmed from a confrontation “in which (Valadez) was trying to silence family members who were potential witnesses” to an alleged sexual assault that occurred two days prior. Valadez was also charged with felony sexual assault for the alleged abuse. Those charges were dismissed as part of his plea to the murder counts. Valadez also admitted a special circumstance allegation of committing multiple murders, which can trigger a sentence of life in prison without the possibility of parole. Sentencing is scheduled for Nov. 15.