According to the Texas Department of Public Safety, 27-year-old Officer Blademir Viveros did not have his emergency lights at the time of the deadly crash.
The victims, identified as 53-year-old Angela Stewart, a Houston ISD counselor, and her 16-year-old son Mason Stewart, were hit by the Missouri City police car on June 20 after an officer received a call of a robbery in progress. Viveros was said to be driving over the posted speed limit in the 1600 block of Cartwright Road.
ORIGINAL REPORT: 16-year-old 'died on his birthday' when Missouri City police car hit him and his mom, dad says
The officer was responding to an ATM robbery and was heading eastbound in the 16-1700 block of Cartwright Road when the Stewarts pulled out of a Dollar Tree parking lot. That's when the officer T-boned their vehicle, police said.
In a release on Thursday, Missouri City PD said the Stewarts failed to yield the right of way before being hit by the police car.
Mason had received his license recently and was driving, officials added. He and his mother died at the scene. The family of the victims told ABC13 it was Mason's 16th birthday.
Viveros was taken to a hospital but was released shortly after.
Witnesses described the crash, saying they heard a loud sound and then saw the police cruiser crush the other vehicle and catch fire. Hours after the crash happened, a person was found in the back of the police cruiser, authorities told ABC13.
The person in the backseat of the cruiser has been identified as 53-year-old Michael Hawkins. Police said he was taken to Ben Taub Hospital, where he is still being treated. Missouri City police will not tell ABC13 why Hawkins was in the back of the vehicle but confirm he was not doing a ride-along.
Hawkins' friends told ABC13 he is paralyzed from the waist down and is on life support at the hospital.
RELATED: Mother who was hit by Missouri City PD officer in crash that also killed her son was HISD counselor
Video shows first responders frantically pulling him out of the cruiser to give him aid. However, police haven't been able to explain why that person was in the back of the patrol car or why it took so long to discover the person was there. Last week, police said they are still investigating why he was in the cruiser as it goes against policy for officers to respond to calls if they already have someone in custody.
Missouri City police said the officer has been with the department for just under a year. He came to Missouri City from a prior agency, where he had about two years of experience.
Viveros has since been relieved of duty as the investigation continues.
"The Missouri City Police Department wants to assure the public we are committed to maintaining the trust and confidence of the community we serve," the department said in a statement.
Police said once the investigation is complete, it will be submitted to the Fort Bend County District Attorney's Office for review.
Viveros' family told ABC13 they have no comment.
The Stewart family sent ABC13 this statement on Thursday afternoon:
"The family of Angela and Mason Stewart continue to grieve and process this tragedy. We are trying to stay focused on supporting each other and our friends, family, and loved ones. We lost our beloved wife, mother, brother, and son because of the dangerous actions of a Missouri City police officer. We hope this decision helps to avoid more tragedies and saves another family from experiencing the sorrow of losing two loved ones. We also hope to see more changes to ensure safer police procedures in serving our wonderful community."
For updates on this story, follow Daniela Hurtado on Facebook, X and Instagram.