SAN ANTONIO – A veteran of the San Antonio Police Department has been arrested for an off-duty incident that happened in late September, police said.
Officer Mark Castillo was arrested on suspicion of aggravated assault with a deadly weapon, police said.
An arrest warrant obtained by KSAT Investigates states Castillo had an altercation with a man over a parking dispute at the Shops at La Cantera.
The affidavit states Castillo pulled out a gun, fired at the direction of the victim, shattering the car’s rear window.
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Police said Castillo has been placed on administrative duty.
He has 25 years of service with the department’s patrol division. Previously, he served on former Chief William McManus’ security detail.
A KSAT Investigates report from 2024 revealed he sent sexually explicit text messages to a woman while on the clock.
In May 2025, he shot a man, later identified as Sheldon Malachi Butts, outside a restaurant on the North Side after he charged at Castillo, records show.
Affidavit: Castillo fired gun during altercation with DoorDash driver at La Cantera
According to the affidavit, a DoorDash driver told investigators that a man, later identified as Castillo, approached him about parking at the Shops at La Cantera, leading to an argument.
Castillo allegedly lifted his shirt, showing his gun on his waistband, the affidavit states.
The affidavit states Castillo removed the gun from his waistband, pointed it down, and asked: “What do you want to do?”
Nearby witnesses helped separate the two, the affidavit states.
After the driver finished his delivery, he said Castillo approached him again, and the two had another altercation.
The driver told investigators he attempted to leave and take a picture of Castillo’s license plate when Castillo allegedly fired his gun, shooting out the back window of the driver’s vehicle.
Investigators used surveillance footage to help identify Castillo after he left the scene, according to the affidavit.
In an interview with police, Castillo acknowledged being involved in the altercation but said he only displayed his weapon and punched out the vehicle’s back window.
Investigators also reviewed video recorded by a witness that allegedly shows Castillo raising his gun before the sound of a gunshot is heard, according to the affidavit.
Castillo previously investigated over explicit texts
In July, 2024, KSAT Investigates reported that records showed Castillo, while assigned to the chief’s detail, sent sexually explicit text messages to a woman during work hours.
Many of the messages were sent during his assigned shift, and some referenced being with McManus, according to the records.
SAPD suspended him for 30 days and was removed from McManus’ executive detail.
KSAT learned Castillo was suspended in October 2024.
Castillo is the 10th SAPD officer arrested this year.
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