SAN ANTONIO -- San Antonio Police Chief William McManus defended his department's use of grant money for extra DWI patrols after a KENS5 I-Team investigation revealed officers who made more arrests were more likely to be assigned to these shifts.

The I-Team examined arrest data for the DWI Selective Traffic Enforcement Program (STEP) patrols for major holidays from July 2012 to September 2013.

STEP is a TxDOT-funded initiative that pays local law enforcement officers overtime to spot drivers disobeying traffic laws.

Hundreds of thousands of dollars are given to SAPD officers every year to work overnight STEP DWI patrols.

According to the data, SAPD officers who made three or fewer arrests during holiday-week patrols were part of the next holiday patrol 70 percent of the time.

SAPD officers who made four or more arrests were part of the next holiday patrol 88 percent of the time.

Finally, SAPD officers who made eight or more arrests were part of the next holiday patrol 100 percent of the time.

The Texas Transportation code states that it is illegal to evaluate, promote, compensate, or discipline a peace officer according to the officer's issuance of a predetermined or specified number of arrests.

"Just because someone has a higher number of arrests and is preferred over someone who may have fewer arrests, it does not mean there's a quota," McManus said.

The program takes a lot of intoxicated drivers off the street. The program makes it safer for the driving public and anybody on the roadways.

McManus said several factors determine who is assigned to future STEP patrols; first and foremost, whether the officer even signs up for a particular shift.

Officer Brent Smith, special events and traffic grant coordinator for SAPD, said a computer determines who is assigned to the patrols.

The number of officers required for a shift fluctuates based on the time of year.

Shifts typically run Wednesday through Sunday from 11 p.m. to 4 a.m., but that can change based on major holidays or special events, such as Fiesta.

Smith said officers make time-and-a-half pay to work the shifts.

Ernest Acevedo III, a prominent San Antonio DWI attorney, said SAPD officers have admitted to being pressured into making arrests while under oath on the witness stand.

"When you start telling an officer he has to arrest a certain number of people, everyone should have a problem with that," Acevedo said.

He said officers with a financial motive to stay on overtime DWI patrols could run the risk of making traffic stops without probable cause.

"If supervisors are telling people, 'Hey, your numbers aren't good enough, you're not going to be able to work STEP anymore,' you're telling them they need to make more arrests. That's the problem."

Part of the conflict appears to be how the STEP grant is written.

While the grant states it does not require officers to issue a specific number of citations, it does set specific targets and goals.

In the case of DWIs, one arrest is expected per six-hour shift.

Earlier this month, SAPD allowed the I-Team to ride along with an officer on a STEP patrol.

Officer Ernest Stevens, a 19-year veteran of the department who works in SAPD's Mental Health Unit, said he has never been pressured to fill an arrest quota while working STEP.

Stevens said he has made multiple DWI arrests in a single night and still wasn't assigned for the next STEP patrol.

State Rep. Joe C. Pickett, the chairman of the state's Committee on Homeland Security & Public Safety, asked the attorney general in November 2013 whether the same rules prohibiting quotas for arrests also apply to warnings.