SAN ANTONIO, TX — (CNN) The unreleased video that police say shows deputies fatally shooting Gilbert Flores in Texas last week appears to show “that he has something in his hand,” Bexar County Sheriff Susan Pamerleau told reporters Wednesday.

Authorities say they think Flores had a knife in his hand when he was shot, and they are asking the Texas Department of Public Safety’s crime lab to “enlarge and to slow down the sequence” so investigators can get “a better idea of exactly what he had in his hand,” she said.

She said the video covers a longer period of time and is recorded from a different angle than a cell phone video that has been shown by the news media.

Michael Thomas was just taking a quick break from his job working on a house in a neighborhood outside San Antonio, Texas, when he noticed a lot of commotion. Ambulances and police cars had pulled up at a nearby home.

He thought, “There’s a lot of things going on in the world,” he told CNN on Wednesday, and he decided he’d do what he had seen so many other people in the news doing lately. He pulled out his cell phone, ready to record if needed.

“It happened so fast,” Thomas said.

Standing across the street, Thomas saw — and recorded — two Bexar County sheriff’s deputies and a shirtless man. The man, Gilbert Flores, raises at least one hand in the air and is then shot and falls on his back. He died.

“Why did they shoot him?” Thomas said on CNN’s “New Day.”

The man, from what Thomas could see, “wasn’t attacking” the officers. “At the time he was shot, it didn’t look like he was posing a threat at all.”

“As the guy and police were going back and forth, the man acted like he was going to run back inside his house, and then ran around the cars by the cop car, and the cops started pursuing closer to him,” Thomas said.

Because Thomas’ video is shot from a distance across a street, it’s impossible to hear what the officers or Flores might have said.

The FBI opened a federal civil rights investigation into the incident “to determine whether a civil rights violation took place as a result of a deputy willfully engaging in the use of excessive or unjustified force,” the agency’s San Antonio office said Wednesday.

Authorities are examining the footage Thomas took and another video of the incident that has yet to be made public. The police have it and have not released it.

The second video shows Flores holding a knife as he’s shot, a source with knowledge of the investigation told CNN on Wednesday. The suspect had both hands up, but he held a knife in one of his hands, according to the source.

Bexar County District Attorney Nicholas LaHood told CNN that the second video is “a better view to make an assessment on what happened. It is a closer view and a better angle.”

He also characterized the second video as “troubling,” and said the FBI has joined the investigation into Flores’ death.

Thomas told CNN that he “assumed the man had both hands up but he did not actually see that,” he said. In his video, the man’s left arm is obscured by a utility pole.

U.S. Rep. Joaquin Castro, D-Texas, who represents the area, urged that the second video be made public.

“I hope the Bexar County Sheriff’s Office will release the second video in the Gilbert Flores shooting as soon as possible,” he tweeted Tuesday.

A domestic violence call

Thomas told CNN’s “New Day” that after he finished recording the four-minute video, he went back to work and told co-workers about it. They urged him to give it to the media.

It didn’t make sense to him to hand over what he’d captured to police, he said.

CNN affiliate KSAT first broadcast the video, and CNN obtained the footage.

The incident comes at a time when law enforcement officers are under scrutiny for how and when they resort to lethal force. The killings of several people by police over the past year have heightened tensions with the communities they serve, especially among minorities.

Authorities were called to Flores’ home Friday for a report of domestic violence. Dispatch communication shows that a woman in the house had a gash on her head and that her baby may have been injured, too.

Flores resisted arrest, authorities say

Bexar County Sheriff Susan Pamerleau said that Flores resisted arrest and nonlethal force — stun guns and shields — were used to try to subdue him, but those methods didn’t work.

“Certainly what’s in the video is a cause for concern,” she said. “But it’s important to let the investigation go through its course so we can ensure a thorough and complete review of all that occurred.”

Pamerleau said both deputies fired shots after a “lengthy confrontation.”

The deputies, who are now on administrative leave, are Greg Vasquez and Robert Sanchez, the sheriff’s office said.

CNN has attempted to contact them but has been unsuccessful so far.

Each has been with the sheriff’s office for more than a decade, Pamerleau said.

Flores had previous run-ins with the law. He was cited for possession of marijuana in 1995, criminal trespassing and aggravated assault in 1999, and aggravated robbery in 2003.

‘Threats to our deputies’ lives’

KSAT posted the entire video on its website. “Other than editing for language, the video is the entirety of what we received from Michael Thomas,” it said.

The station told the sheriff’s office about the video and sent it there, but the station did not give any warning that it would post the entire raw video Monday, said James Keith, media relations officer for the Bexar County Sheriff’s Office.

Now, Keith says, the sheriff’s office is worried about the safety of its deputies in light of the video’s public release. On Monday, it tweeted a statement that said “broadcasting a man’s death for $100 sparked threats to our deputies’ lives. Let KSAT know what you think.”

In a post on its website, KSAT explained its decision to show the video and the discussions station management had with Thomas.

“Before sharing the video with us, Thomas asked for payment. While most viewers share video with us at no charge, we agreed to pay Thomas a $100 licensing fee for the video. It is not uncommon for news organizations to pay for video from freelancers or citizen journalists.”

The station said it was making no judgment about the officers’ actions, but it was obligated to share “information in the public interest.”

When asked about the sheriff’s office tweet, Keith cited the case of Darren Goforth, a deputy who was shot from behind and killed while filling up his car at a gas station.

“After what happened in Harris County, we are not going to take any chances,” he said. “Now our deputies are coming to work in civilian clothes because of their concern for safety.”

Hours later, the sheriff’s office sent out a message with the following statement: “In regards to the deputy involved shooting, we’re asking for calm and patience. We are diligently working to complete the investigation so we can move to the next step. We want to get this right for the Flores family, our deputies and our community.”

In an opinion piece, CNN legal analyst Danny Cevallos reminded readers that several things that the video didn’t include will be crucial issues in an investigation. For one, the video doesn’t provide audio of the exchange between the police and Flores.

Any threats of violence would be important to consider, he writes.

More officer cameras

The administrative body in Bexar County, the Commissioners Court, on Tuesday approved a budget that included 185 cameras for the sheriff’s office.

Thirty-four of the units can be used as a dashboard recorder and a body camera.

Neither deputy involved in the shooting was wearing a body camera.

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