HARRIS COUNTY, Texas -- Harris County has the highest number of exonerations in the country when it comes to drug charges, according to a recent study.

National Registry of Exonerations released statistics Tuesday that show there were 61 drug-related exonerations in the United States in 2016. Harris County was responsible for 48 of those exonerations.

In many of those cases, people were arrested based on field tests, then lab tests revealed the substance they were caught with wasn’t a drug at all.

“It’s a good thing because that means we’re still diligent, even after the person has pled guilty to be sure that he is guilty,” said Tom Berg, First Assistant, Harris County District Attorney’s Office. "We follow through with sending material to the lab to have it analyzed.”

The DA’s office also has a special department called the Conviction Integrity Unit, which is specifically tasked with finding and correcting bad convictions.

However, some wonder why people are being falsely accused in the first place.

Ross Lebeau, a Cypress resident, was arrested in December after Harris County Sheriff’s Deputies discovered what they thought was methamphetamine in a sock in his trunk. Field tests confirmed their suspicions.

The 24-year-old says he was charged with a felony and held in jail for four days.

“I thought it was some kind of deodorizer or something like that, something makeshift. I definitely never thought it was meth ever” Lebeau said.

He was right.

It turns out the substance was cat litter his dad put in the car to keep windows from fogging up.

Lab tests cleared Lebeau’s name a month later, but he says the damage was already done.

“If they’re going to file against someone and they’re going to prosecute, they need to have the information correct up front,” Lebeau said. “We pay our taxes, and for what? For our protection? Then they use drug tests they know are faulty, and they don’t do anything about it? I’m just a small case in a bigger crime.”

However, prosecutors say the field tests officers currently use are necessary.

“That’s not proof beyond a reasonable doubt, that’s merely probable cause which supports an arrest. Then the substance goes off to the lab, and the person in many cases goes off to jail,” Berg said. “I don’t think we have sophisticated tests that can go to the street level at the time of arrest to make that determination. It does require lab analysis.”

Berg said he expects the number of exonerations to go down in the future because of new policies being implemented by District Attorney Kim Ogg.

One new policy involves misdemeanor marijuana charges. Now people caught with smaller amounts of the drug are able to avoid convictions by enrolling in a class instead.

The District Attorney’s Office is also considering bail reform.

“We’re looking at reforming bail, so people are released from jail, and they don’t feel like they have to plead guilty when there’s uncertainty about the substance just to get out of the jailhouse,” Berg said.