Tad Cummins, the former Tennessee teacher accused of kidnapping 15-year-old Elizabeth Thomas before being caught in California was indicted by the federal grand jury Thursday, reports said.

The 50 -year-old was indicted on one charge of illegally transporting a minor across various states for the purpose of engaging in sexual activities which carries a maximum sentence of life in prison. He was also charged with destruction, alteration or falsification of records in a federal investigation which carries a sentence of up to 20 years in prison, CNN reported.

The kidnapping charge comes due to Thomas being underage, who cannot legally consent to sexual activity or being taken across state lines. The obstruction of justice charge was related to Cummins destroying his and the girl’s mobile phones, the Tennessean reported.

There are also state charges against him for sexual contact with a minor and aggravated kidnapping which Cummins already pleaded not guilty to, according to CNN.

ReadFBI Agent: Tad Cummins Had Sex With Elizabeth Thomas 'Most Nights' During Alleged Kidnapping

Cummins was arrested on April 21, five weeks after he took Thomas from Columbus, Tennessee on March 13. He was suspended from Culleoka Unit School in Maury County after some students informed the authorities they had seen Cummins kissing Thomas in the classroom, said a report.

While on the run, Cummins had disabled the GPS of his car, thrown away his mobile phone and even taken on a false name, it was reported.

A nationwide manhunt was launched to find them and after receiving a tip-off from a property caretaker, police finally managed to capture them in Siskiyou County, California near the Oregon border where they had been living.

Griffin Barry, a native of Tennessee, was awarded $10, 000 for assisting the police in locating Cummins and Thomas, said the report. The former health science teacher was then taken back to Tennessee on May 9 to face criminal charges, said the Tennessean report.

During the investigation, police discovered Cummins, a grandfather, had left a note for his wife before fleeing with the teen. As police looked for more evidence in the case, they came across an Instagram account of Thomas where she had changed her bio and added the title of ‘wife’ with an emoji of a ring. Police also spoke to Thomas’ father, Anthony, who told them Cummins used to stalk and threaten his daughter long before he kidnapped her, AL.com reported.

ReadTad Cummins And Elizabeth Thomas' Story: The Latest Since They Were Found

Days after the pair went missing; they were captured on the CCTV camera of a Walmart store in Tennessee. Police believe they often bought hair dye from various stores to keep their identity secret. After being found, Thomas was sent to a rehab facility where she was kept for some time before being united with her family.

Despite her being underage, the preliminary hearing saw the former teacher’s lawyers arguing Thomas was not held against her will and that she willingly fled with Cummins. 

Cummins, who already denies the state charges, is expected to have a trial soon and if convicted, could face life in prison as well as a $500,000 fine.