A manhunt is underway in Texas for an escaped prisoner who evaded authorities by running into a heavily forested area as he was being transported from Gatesville to Huntsville.

Convicted murderer Gonzalo Lopez, 46, continues to be on the run after escaping from custody three weeks ago, on May 12. Lopez escaped from a prison bus while being transported for a medical visit and stabbed the driver.

Authorities have released photos taken of Lopez before he boarded the bus, including images of identifying tattoos across his body. Lopez has a tattoo across his lower back that reads “Aztlan,” one on his upper back that says “Mexican” and one across his stomach that says “Gonzo.” There is currently a $50,000 reward for information leading to his arrest.

Courtesy of U.S. Marshals Service

“He’s crafty,” Texas Department of Criminal Justice spokesman Robert Hurst said. “He’s done this before down in South Texas in Webb County, he hid out for almost nine days.”

Lopez had both his hands and feet restrained and was sitting in a caged part of the bus designated for high-risk inmates. After breaking free from his restraints, he cut through the cage and attacked the driver, who was left with non-life-threatening stab wounds following their altercation.

Lopez was then approached by a second officer, but by that point he had already hijacked the bus and started driving away. The officers fired at the bus and stopped it by shooting out one of the rear tires. The bus kept going down the road for a bit, at which point Lopez exited and escaped in the nearby woods. According to CBS News, “Sixteen prisoners were aboard the bus, but no one else escaped.”

Witnesses to the ordeal, Melanie Tieperman and her son, filmed Lopez’s escape on her phone.

Fox News reports: “The ‘heavily tattooed’ fugitive, described as a White or Hispanic male standing approximately six-foot tall and weighing 185 pounds, also has distinct artwork inked on both arms and his chest.”

Lopez was convicted of murder in 2006 after “killing a man along the Texas-Mexico border.” He escaped in Leon County, which is a rural part of Texas that sits between Dallas and Houston. Current search parties are pursuing Lopez via aircraft and horseback, with canine teams also searching for the escaped convict.