President Obama on Thursday justified his decision to commute the sentences of 53 people with gun charges this week by saying he worked hard to focus on people who didn't seem to have a real history of gun violence, and may have only faced charges for carrying guns.

Obama has pushed to reduce federal sentences over the last few years, but at the same time, he has pushed several times for tougher gun control laws. But Obama said his commutation decision this week was consistent with both priorities.

"What I've done is ... try to screen out folks who seem to have a propensity for violence," Obama said in a press conference at the Pentagon Thursday.

"These are just hypotheticals, but there may be a situation where a kid at 18 was a member of a gang, had a firearm, did not use it in the offense that he was charged in, there's no evidence that he used it in any violent offense," he explained.

He said that people with good records after 20 years in prison, who may have gotten their GEDs, drug treatment or other programs, were among those qualified for his commutation.

"In that situation, the fact that he had 20 years earlier an enhancement because he had a firearm, is different than a situation where somebody is engaged in armed robbery and shot somebody," he said. "Our focus really has been on people who we think were over-charged, and people who we do not believe have a propensity toward violence."