Story highlights Harris County Deputy Constable Tommi Jones Kelley refuels her patrol car

A teen asks to stand behind her -- to watch her back

Fellow Harris County Deputy Darren Goforth was killed at gas station on August 28

(CNN) When a Texas teenager provided "backup" for a law officer pumping gas alone in the rain near Houston, she snapped a selfie of the two of them. It has gone viral.

Harris County Deputy Constable Tommi Jones Kelley posted the photo this week to Facebook and wrote, "this teenager I've never met before is standing right behind me & says, 'ma'am, do u mind if I stand here behind you while u get ur gas?'"

She asked him why. The young man, whom she identified as Mckinley Zoellner, answered "to make sure You stay safe!" Kelley wrote. The post had been shared 181,000 times by early Sunday.

The gesture delighted Kelley, particularly in light of the killing of a sheriff's deputy at a gas station a little over a week ago.

Fellow Deputy Darren Goforth was shot dead on August 28 while refueling his patrol car. The 10-year veteran was in uniform at the time. Officials described it as an "execution-style" attack.

Read More