HOUSTON -- Evidence in the case of a tow-truck driver suspected of killing a couple coming home from church may be lost because of a problem with a police camera at the scene, KPRC Local 2 reported Friday.

Leon Roberson, 78, and Maureen Roberson, 67, were killed in the 11600 block of Wallisville Road near Colvin Street at about 9:15 p.m. on Oct. 18. They left their Bible study at Blessed Hope Missionary Baptist Church a few minutes before the crash occurred.

Police said the wrecker was going at least double the posted speed limit of 45 mph and there were no skid marks on the pavement.

Officials said the camera malfunctioned at the scene. The district attorney's office said the camera issue has been troubling to the district attorney's office.

"When you go tell (victims' families), 'Sorry, we should have done a better job,' it's disheartening and it's hard. And it's the victims we're worried about," assistant district attorney Paul Doyle said.

The district attorney's office is worried that fatal traffic cases may be weakened by the camera problem.

Doyle said it's a matter of getting better and newer equipment for the officers and training them properly.

"You've got officers out on the roadway, risking their lives and sometimes they don't have the proper equipment. It'd be nice if they had video cameras, if they had cameras, if they had the paint that's necessary to mark the scene. Some officers don't have that," Doyle said.

A Houston police spokesman said the problem is already being addressed.

"They may have equipment that's a little older and it's beginning to malfunction that needs to be upgraded. We understand that. That's why we've purchased almost nine laptops, the software. We've purchased 35-millimeter digital cameras, " said Capt. Dwayne Ready with the Houston Police Department.

The department also purchased camcorders.

However, the officers still need to be trained. HPD said it spent $90,000 to train officers on the new equipment. Next year, one sergeant and five officers will attend a training course to make them crime-scene experts.

Houston Mayor Bill White said the malfunction in the case against tow-truck driver Sergio Gonzalez is unfortunate. But, he said he believes the case is still strong.

"I think the medical examiner had a camera and we had officers at the accident scene. We have a blood sample that's undergoing analysis and we have very good people at the DA's office. Nobody's told me that the case can't be prosecuted, " White said.

But, Doyle said, it does not help.

"It doesn't mean that we're not going to be able to prove our case. What it does is it gives a defense attorney an angle to attack, we're talking beyond a reasonable doubt," he said.

With the past six months, the district attorney's office created a vehicular assault team to help gather evidence. Officials said it was necessary after coming up short or with the wrong evidence too many times.