(NewsNation) —  The biggest Texas manhunt in nearly 20 years continues for an escaped convicted murderer who authorities say has ties to the Mexican Mafia.

Gonzalo Lopez, 46, has been on the run since last Thursday after getting out of his handcuffs, stabbing an officer and hijacking a prison transport bus carrying 15 other inmates. One of the guards ended up shooting out the tires of the bus during the ordeal, and that’s when investigators say Lopez ran into a field.

The escape happened near the town of Centerville, a rural area between Dallas and Houston. Authorities believe Lopez used some sort of sharp object as a key tool in his escape.

Making the manhunt their top priority, Texas authorities have combed through more than a 100-mile span of a nearby highway using helicopters, horses and K-9 teams in attempts to track down Lopez. They say the search has been going on 24 hours a day, around the clock, with more than 300 law enforcement personnel involved.

At the time of his escape, Lopez was serving two life sentences for murdering a man with a pickaxe after holding him ransom on a drug debt and trying to shoot a sheriff’s deputy in 2004.

NewsNation has learned from the Texas Department of Public Safety that Lopez does have ties to the Mexican Mafia. Officials told NewsNation senior correspondent Brian Entin that they believe the escape was planned and that it’s possible with Lopez’s gang affiliations, a car followed the prison bus and picked him up.

However, investigators say it’s far more likely Lopez is still hiding somewhere in a wooded area in Leon County.

Robert Hurst is the point man for the Texas-sized manhunt, serving as the public information officer for the Texas Department of Criminal Justice.

“As far as we know, and from everything that we are seeing and hearing, we still think he’s back here. There’s nothing to indicate that he’s not,” Hurst said.

He continued: “This time we’re going to make sure that we get him while he’s still in this area. We’re not going to give up until we get him. Now, if he had help from the Mexican cartel last time, we don’t think he got that this time because we set up a perimeter around this area very quickly after he escaped from that transport bus. Last Thursday afternoon, within a matter of minutes, we had a perimeter set up, with assistance from the local law enforcement agencies in this area, as well as our own personnel and the Texas Department of Criminal Justice.”

Retired Chief Deputy U.S. Marshal Matthew Fogg has many years of experience tracking down fugitives. Fogg agrees with Texas investigators, saying Lopez is likely still in the immediate area.

“Once he was able to overpower the guard that was driving the bus, he had to drive the bus a distance. I’m sure at that point in time, he jumped out so there’s no room to pinpoint as to where he is. Now, of course, what happened last Thursday, I would think after a few more days, I’m sure they’ve expanded their search, even though they’re concentrating on that area where he ran with the dogs and everything else. But the reality of it is they are also checking our records, finding out who he was in contact with and all of that. So there’s a lot of follow-up (besides) just the fact that they are searching that area,” Fogg explained.

How has Lopez been able to successfully remain on the run? Fogg thinks it’s because he’s in his element. Investigators have also reported that Lopez has ties to Weslaco, Mercedes and San Antonio.

“Maybe he’s an avid woodsmen. I don’t know his background, but the reality of it is he’s in his domain. He speaks the language and all of that. He could have ran into somebody. He could just be hiding out in a particularly dark spot, I don’t know,” Fogg said.

Authorities are conducting all kinds of searches, Fogg says, including using helicopters, infrared and everything they can. Still, Fogg thinks if they don’t catch Lopez in the next few days, he may have hitched a ride or forced someone to drive him off somewhere.

Hurst says the Texas Department of Criminal Justice continues to receive information from concerned citizens, despite fear there may be a reprisal from the Mexican Mafia.

“Texans are a hearty bunch, and Texans do not fear the Mexican Mafia,” Hurst said. “So I’m going to tell you right now, the folks that live out here in Leon County, they’re helping us. They know that we’re going through their properties looking for this man, they’re assisting us, they know that we are going to get this man back in custody. … They’re not necessarily concerned about the Mexican Mafia. They’re concerned about Gonzalo Lopez, and they’re doing everything they can to help us get him back in custody.”

Hurst insists the search will not be called off until Lopez is back behind bars.

“He’s going to play a waiting game with us, but we’re going to wait him out. We’re going to get him, we’re not going to back off. We are not going to call this search off until we have him in custody,” Hurst said.

Lopez is on the Texas 10 Most Wanted Fugitives List. He is wanted for escape and aggravated assault of a public servant.

In 1996, the Texas Department of Public Safety says, Lopez was convicted of two counts of aggravated assault and sentenced to eight years in prison.

In 2006, he was convicted of capital murder and aggravated kidnapping in Hidalgo County and sentenced to life in prison. The following year, he received a second life sentence after being convicted of attempted capital murder in Webb County.

“He’s … a very dangerous man. And we’re not going to let him get away from us,” Hurst said.

A $50,000 reward for information leading to Lopez’s arrest has been offered. To be eligible for the reward, the Texas Department of Safety says tipsters must give authorities information in one of the following ways:

-Call the Crime Stoppers hotline at 800-252-TIPS (8477).

-Submit a web tip through the DPS website by selecting the fugitive you have information about and then clicking on the link under their picture.

-Submit a Facebook tip by clicking the “SUBMIT A TIP” link (under the “About” section).

Texas 10 Most Wanted fugitives are considered armed and dangerous. Anyone who sees Lopez is urged not to approach him, but instead call 911.