A grand jury on Thursday returned murder charges against a Harris County sheriff's deputy and her husband after the pair were involved in the choking death of a man outside a Denny's restaurant in May, District Attorney Kim Ogg announced.

Flanked by Harris County Sheriff Ed Gonzalez, Ogg alleged Deputy Chauna Thompson and her husband, Terry Thompson, are responsible for the death of 24-year-old John Hernandez after he and Terry Thompson got into a fight.

"We believe that a just result for the victim, the offender and the community are important and this requires equal application of the law to everyone," Ogg said. "And today we move one step close to justice for John Hernandez."

The charges come after a single day of grand jury testimony in a Houston courtroom, where witnesses to the fight told jurors what they saw that evening.

The Thompsons are expected to turn themselves in, when they will be booked into the Harris County Jail. They face up to life in prison if convicted. Chauna Thompson, who had been on active duty from the day of the incident until Tuesday, has been suspended.

Dane Schiller, Ogg's spokesman, said the district attorney's office was unable to recall the last time a police officer faced a murder charge in Harris County.

The investigation moved swiftly after the release on Tuesday of a cell phone video, shot by a bystander, depicting the altercation between Hernandez and the Thompsons.

In the 52-second clip, the husky Terry Thompson can be seen on top of Hernandez, grasping Hernandez in a chokehold. Kneeling beside them, Chauna Thompson orders Hernandez to stay on the ground, as Hernandez groans and flails his legs. Blood is visible on Hernandez's hands and the sidewalk.

Hernandez died three days later. The Harris County Medical Examiner's Office on Tuesday declared his death a homicide caused by strangulation and chest compression — a finding supported by the video clip.

On Wednesday, Sheriff Gonzalez and D.A. Ogg promised a thorough investigation that would ultimately be heard by a grand jury — all while more than 150 demonstrators marched through downtown Houston, demanding charges be brought against the Thompsons.

According to the sheriff's office, the fight began when Terry Thompson arrived at the restaurant with the couple's children after 11 p.m. on May 28, and became upset when he allegedly saw Hernandez urinating in public — a claim the Hernandez family denies. At some point after Terry Thompson confronted Hernandez, the pair began fighting. Chauna Thompson, who was off duty, arrived to meet her husband and children. She saw her husband and Hernandez fighting, called for on-duty police to respond, and helped subdue Hernandez.

Randall Kallinen, who represents the Hernandez family, did not immediately return a request for comment. Nor did Scot Courtney, who represents Terry Thompson.

