NEW SMYRNA BEACH, Fla. -

Volusia County deputies arrested George Zimmerman's mother-in-law for suspicion of driving under the influence of prescription pills.

Drivers on SR 415 near Osteen were in a panic, and can be heard in 911 calls begging deputies to pull over the swerving car.

"Oh, he just ran off the side of the road. Now he's back on. Now he's in the other lane. Oh my God, there's traffic coming!" a 911 caller said.

That caller was right in front of the weaving car, that deputies said was driven by Machelle Smothers Dean, 53, of Lake Mary. Local 6 has learned Dean is Shellie Zimmerman's mother and George Zimmerman's mother-in-law.

Some drivers swerved, others slowed down or pulled over to avoid crashing into an out of control car, reported the callers. Witnesses said the reckless car they spotted on August 8 was going nearly 60 miles per hour, almost hit construction cones and a pedestrian. Frantic, some decided to take action and stop the driver.

The women who drove behind her and saw everything also called 911 and told the dispatcher: "There is a car swerving all across the lane. She's about to wreck into a semi!"

That's when the two women driving in the car behind Dean, boxed in her car when it stopped in a driveway. The family took her keys, waited for authorities, and may have saved lives.

"God put us behind her to save everybody's life that day," said Brittany Biefeldt, who was sitting in the passenger's seat and called 911.

Although her baby was in the backseat with them, Biefeldt and the driver, Jessica Osteen, felt the driver was too dangerous to stay on the road without someone intervening.

According to the police report, Dean told deputies she took two hydrocodone pills before she got behind the wheel, but is also prescribed Xanax and another sedative.

Biefeldt and Osteen had no idea who they stopped that night, but when they learned the driver is related to George Zimmerman, Biefeldt said, "She obviously was not thinking and being under a lot of stress and her daughter being in trouble now too. She I guess wanted to forget about it."

Local 6 reached out to both Shellie and George Zimmerman's attorneys for comment about this arrest, but have not heard back.