By Brian New

Bexar County, TX (KENS/CNN) - A sheriff's deputy in Texas is on leave while investigators look into the deaths of his two police dogs.

The canines died from heat exposure because they were left in a patrol vehicle overnight.

It wasn't supposed to happen. Not again, not to another K-9, not to two more at the Bexar County Sheriff's Office. But it has.

Deputy Steven Benoy has been placed on leave after leaving his two K-9s in his patrol car. Both dogs died from the heat.

Two years ago another k-9 died in a Bexar County Sheriff's patrol vehicle. The sheriff's office said the K-9 named Duke was sick, and that's what lead to his death. In the months that followed the sheriff's office talked about installing alarms that would go off when a K-9 unit got too hot.

The sheriff's office would not confirm Thursday whether a sensor had ever been put in Benoy's vehicle.

Last year, state lawmakers considered making the alarms required for all law enforcement K-9 units. The bill was never assigned to a committee.

Don Barnes with Voices for Animals says it's unacceptable.

"I'm pretty upset by that kind of irresponsibility and hope that changes can be made in the very near future," said Barnes.

In a statement from the sheriff's office, Deputy Benoy is "completely devastated by this tragic accident."

Two years ago in a KENS5 interview, Benoy told us what it would be like if one day something happened to his K-9 partners.

"It would be just like losing a member of your family. I'm sure when a K-9 officer loses his companion, we all mourn," Benoy said.

A prophetic statement perhaps made by a now-devastated officer.

The officer involved in the incident is a 23 year veteran who has been assigned to the K-9 unit for 13 years.

KENS/CNN