The witness blocked traffic around the wounded security officer and directed police toward a suspect who had left the scene.
DALLAS, Texas — A truck driver who witnessed a violent confrontation at a northwest Dallas gas station used his vehicle to shield a critically injured security guard from traffic before helping police locate the man accused of attacking him.
Michael Black was near the Fuel City in the 2400 block of West Northwest Highway on Saturday night when security guard James Johnson was seriously injured during a confrontation. Dallas police accuse 46-year-old Rosalino Lopez of assaulting Johnson with a metal rake. Johnson remained hospitalized in critical condition as of Monday evening.
Police said the incident began after Lopez damaged a breaker box at the gas station where Johnson, an employee of CDS Protective Services, was working. Johnson confronted Lopez, who police said became combative. Investigators said the encounter escalated from a physical struggle to an assault involving the rake.
Johnson used a Taser during the confrontation, according to police, but it did not stop the suspect. Johnson eventually collapsed in the roadway near the business after suffering critical injuries. Lopez then left the immediate area, investigators said.
Black said he saw Johnson fall and realized the injured guard was vulnerable to vehicles traveling along the roadway. He moved his truck into position to block traffic while waiting for first responders. Black also called 911 and remained near Johnson as emergency crews were dispatched.
The witness later helped officers identify the direction in which the suspect had gone. Police said Black pointed officers toward Lopez as he walked along the highway, allowing authorities to locate and arrest him nearby.
Investigators said a metal rake was later found in a shopping cart associated with Lopez. Police allege the object was used in the assault. Dallas County jail records list Lopez on an aggravated assault charge involving a security officer. An arrest and criminal charge do not establish guilt.
Dallas Fire-Rescue took Johnson to a hospital after arriving at the scene. CDS Protective Services later confirmed Johnson’s employment and thanked the firefighters and police officers who responded, including those who provided emergency care and continued the investigation.
The witness intervention became a key part of the immediate response: Black protected Johnson from passing traffic while medical help was coming and then provided officers with information that helped them find a suspect. Police assault detectives continued investigating the case after crime scene personnel processed the area.
Johnson remained in critical condition as of Monday evening. Lopez was booked into the Dallas County Jail as the criminal case and police investigation continued.
Author note: Last updated August 18, 2026.