A veteran of the San Antonio Police Department has been arrested for an off-duty shooting at La Cantera 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 on Sept. 26.
The affidavit states Castillo pulled out a gun, fired at the direction of the victim, shattering the car’s rear window.
>>READ MORE: SAPD identifies officer who shot, critically injured suspected thief twice on North Side
Police said Castillo, who has 25 years of service and is assigned to the department’s patrol division, has been placed on administrative duty.
This arrest marks Castillo’s latest trouble involving allegations of misconduct.
Previously, he served on former Chief William McManus’ security detail.
A KSAT Investigates report from 2024 revealed Castillo sent sexually explicit text messages to a woman while on the clock.
Separately, 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 and asked for his gun, records show.
Castillo was not charged in connection with that shooting and was not disciplined for it.
According to the arrest 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 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 fired his gun, shooting out the back window of the driver’s vehicle, records show.
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 shows Castillo raising his gun before the sound of a gunshot is heard, according to the affidavit.
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.
>> Member of McManus’ security team sexted with woman while on duty, records show
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 removed him from McManus’ executive detail.
KSAT learned Castillo was suspended in October 2024.
On May 9, 2025, Castillo shot Butts outside the Thai Hut Restaurant location in the 2600 block of North Loop 1604 West near Bitters Road.
According to the body-worn video, the employee told Castillo that Butts “took one of the scissors from the kitchen” after placing a food order.
>> SAPD releases body camera footage of police shooting outside North Side restaurant
Castillo asked the employee if Butts still had the pair of scissors on him.
“We don’t know,” the employee told Castillo. “He came back into the restaurant.”
Police said Butts then fled behind the building. Castillo found Butts standing in the restaurant’s front parking lot, the video indicates.
According to the video, Butts asked for Castillo’s gun “so I can kill myself.”
“I’m not going to give you my gun, brother,” Castillo said to Butts, according to the footage.
Video shows Castillo asked Butts to have a seat so they “can talk.” According to the footage, Butts looked elsewhere before taking two steps toward Castillo, who backed away and radioed to fellow officers to “step it up.”
Butts then charged at Castillo, who deployed his pepper spray at him. Castillo began running away from Butts and toward the Thai Hut Restaurant’s front door.
Butts chased after Castillo, the body-worn video shows.
The body camera video then froze for five seconds. When the video resumed, Butts and Castillo were seen in a struggle. SAPD said Butts attempted to reach for Castillo’s “holster.”
The struggle caused Castillo’s body-worn camera to be tossed to the ground at the 1:27 mark of the video.
While it is unclear what is happening for the remainder of the video, at the 1:46 mark of the video, two gunshots were heard and the sound of someone grunting in pain.
Butts was transported to a local hospital in critical condition. He was charged with assaulting a peace officer and taking a weapon from an officer.
Castillo is the 10th SAPD officer arrested this year.
