TAMPA, Fla. — Hundreds of bus drivers in Hillsborough and Pinellas Counties will now have a new layer of protection against potentially dangerous passengers. 

More than $1 million of plexi-glass safety shields are being installed on 180 Hillsborough Area Regional Transit Authority buses and 12 HARTFlex vans. 

Each shield is equipped with an interior latch which operators can slide-lock while in their seat compartment. 

The installation of these shields comes five months after a HART bus driver was stabbed to death by a passenger.

On May 18, bus driver Thomas Dunn was fatally stabbed by 35-year-old Justin McGriff, according to authorities. 

The incident occurred at North Nebraska Avenue between East Lotus Avenue and North Castle Court, south of East Linebaugh Avenue.

Surveillance images show McGriff sitting at the back of the bus before getting up and walking toward the Dunn. 

After a brief conversation between McGriff and Dunn, the next image shows McGriff swinging a knife toward Dunn, striking him in the throat.

In spite of his injuries, authorities said Dunn managed to steer the bus to safety before slumping in his seat.

McGriff fled the scene and was captured by police near I-275.  McGriff remains in the Hillsborough County jail. 

Several safety measures have been taken since Dunn's death, like increasing security at transit centers.

In June, HART announced it would be adding safety barriers to all buses and vans.  Those safety measures are now being put in place. 

The new-safety shields will be rolled out to the public on a regular schedule over the next few weeks. 

Pinellas Suncoast Transit Authority is also retrofitting its buses with similar shields.  The started the project a year before Dunn was killed but accelerated the project after his death. 

"We fast tracked by ordering 200 more of these to equip the entire Pinellas County bus fleet with these safety barriers," Brad Miller, with PSTA, said.