According to prosecutors, Banda enlisted her brother, Arnold DeLeon, and Castellanos, a friend of her son, to carry out the killing after telling DeLeon that Martinez had assaulted her. The group met the day before the murder at DeLeon’s home in Corpus Christi and agreed Castellanos would drive DeLeon, who was a double amputee, to Rosenberg.
On the night of the murder, Banda gave Martinez a sedative to help ensure the men could get inside undetected, then let them into the home and left a gun for DeLeon in the entryway, prosecutors said. DeLeon shot at Martinez as he slept but missed, waking him and triggering a struggle. Castellanos intervened, and DeLeon ultimately shot Martinez in the back before handing the weapon to Castellanos, who shot Martinez in the head, according to the district attorney’s office.
Banda then asked to be tied up so she would appear to be a victim, prosecutors said. DeLeon drove back to Corpus Christi while Castellanos loaded several of the victim’s firearms into Banda’s pickup truck, which he later sold along with the guns.
Investigators with the Rosenberg Police Department pieced the case together using surveillance footage, license plate readers and cellphone records, prosecutors said. A neighbor’s report of a red Hyundai Veloster near the scene, combined with a falsified license plate number Banda gave police for her stolen truck, helped investigators trace the vehicle to Castellanos, who was later arrested entering the U.S. at the Hidalgo border crossing.
Banda was not charged until years later. A warrant for her arrest was issued in March 2024 after Castellanos agreed to cooperate with investigators. A second, more advanced extraction of her cellphone recovered a deleted text from DeLeon sent just before the killing that read, “outside. open,” prosecutors said.
DeLeon died of natural causes in July 2022 before he could be charged. A neighbor, Karen Rodriguez, pleaded guilty in June 2024 to tampering with evidence for helping dispose of the getaway vehicle and is on probation.
At Banda’s sentencing hearing, Martinez’s two adult children from a previous marriage testified about years of physical, mental and emotional abuse they said they endured from Banda as children. Banda’s defense presented expert testimony that she had been abused by Martinez, but prosecutors said the underlying testing was later deemed invalid and possibly influenced by malingering. On cross-examination, the state introduced text messages showing Banda had been involved with multiple people in the months before the murder, which prosecutors said undermined her abuse claims.
“The truth finds a way to escape even the most evil plots,” Middleton said in a statement. “I commend the great investigative work to expose the truth and allow us to speak for the victim.”
The case was prosecuted by Special Crimes Chief Traci Bennett and Deputy Chief Prosecutor Ashley Harkness. Murder is a first-degree felony in Texas punishable by five to 99 years, or life, in prison and a fine of up to $10,000. Both defendants must serve at least half their sentences before becoming eligible for parole.
