CLEARWATER — In 1987, Robert Aho was driving home when he was struck by a Firebird barreling along U.S. 19 north of Coachman Road.

The driver had been drinking. Robert, 20, and his friend Tony Garten, 22, a passenger in the car, were killed.

After her son’s death, Barb Aho became president of Remove Intoxicated Drivers Tampa Bay — RID Tampa Bay — seeking more attention for the issue of impaired driving in Pinellas.

“You just don’t want anybody else to have to go through what you’ve been through,” she said.

On a recent night, she watched as the Pinellas County Sheriff’s Office set up a DUI checkpoint on the same stretch of congested highway where her son died more than two decades ago. Among the deputies working the checkpoint were members of the sheriff’s DUI unit, reinstated earlier this year.

In 2009 the DUI squad, which at one point had more than a dozen deputies, was eliminated due to budget cuts. The Sheriff’s Office immediately noticed a slump in arrests.

Before the unit was disbanded, the agency had averaged between 1,400 and 1,500 DUI arrests a year, said Sheriff Bob Gualtieri. But from January through September last year, the agencywide total was only 521.

“When I see statistically that our DUI arrests are down by 50 percent,” Gualtieri said, “I know it’s not because of fewer impaired drivers on the road. I wish it was. I really do.”

The new unit, which reached full staff about four months ago, includes six deputies and a sergeant. Between late April and September this year, the unit made nearly 500 DUI arrests. From January through September this year, the agencywide arrest total rose to about 1,200.

“You see a big difference,” the sheriff said.

Gualtieri hopes the number of DUI-related crashes, which totaled about 60 in the first nine months of both 2012 and 2013, will begin to decrease now that the DUI deputies are back on the streets.

The unit is supervised by Sgt. Howard Skaggs, a 26-year Sheriff’s Office veteran who worked on the original DUI squad for eight years.

The unit works Wednesday through Saturday from dusk to dawn. While off-duty, members are often called upon to testify in court hearings involving DUI cases. When on-duty, they spend time in different areas of the county patrolled by the Sheriff’s Office.

Among the factors used to determine what area they’ll monitor: Where are the night’s drink specials?

“Who’s giving the dollar specials? Who’s giving the lady’s night?” Skaggs said. “What is going to be busy?”

To spot an impaired driver, the deputies look for several signs. Is the driver traveling slowly? Failing to maintain a single lane? Signaling incorrectly? Braking two blocks before a turn?

Skaggs said he has encountered several drivers with especially high blood alcohol levels. A handful have rated above 0.30, including a man driving a golf cart in Palm Harbor. The state assumes impairment at 0.08.

A deputy trying to make a U-turn in Palm Harbor recently was slammed by a drunken motorcyclist, spinning his cruiser 180 degrees. That case remains under investigation.

“A lot of people say we’re hunting people down,” Skaggs said. “We don’t have to hide. We really don’t.”

Another aspect of the unit’s job, Skaggs said, is education. If someone tests close to 0.08, the DUI deputies chat with the motorist about the dangers of impaired driving.

“That’s educating as opposed to enforcing the laws. I hate to call it a gray area, but that’s exactly what it is,” Skaggs said. “We get them a cab, we call a friend. They are more educated for it. They are not going to jail for DUI.”

RID Tampa Bay organizes an annual dinner during which it recognizes officers in Pinellas County who have made the most DUI arrests in the past year. In 2012, the sheriff’s deputy with the highest number made 38 arrests, compared to officers from some other jurisdictions who made more than 100, Aho said.

“I was just totally embarrassed with that,” Aho said. “I knew something was wrong.”

This year, the Sheriff’s Office fared better.

Three deputies made more than 100 DUI arrests. Each.

Contact Laura C. Morel at [email protected] or (727) 445-4157.