Colorado movie theater shooter James Holmes was assaulted by an inmate earlier this month at a maximum-security prison in the state, a corrections official said Friday. Holmes is serving life sentence for killing 12 people and injuring 70 others at a movie theater Denver in July 2012.

The incident took place on Oct. 8 when a corrections officer escorted Holmes through a hallway. Adrienne Jacobson, a spokeswoman for the Colorado Department of Corrections, told the Denver Post that the 27-year-old inmate, Mark C. Daniels, charged at Holmes and “took a few swings” at him. Daniels also attacked the officer. Neither Holmes nor the officer was injured in the attack.

Jacobson told the Associated Press (AP) that Daniels will be disciplined during a hearing inside the prison. Holmes, who received life sentence without parole, is allowed to spend four hours in a day hall and no other inmates share his cell, according to AP.

In August, Holmes was also sentenced to over 3,200 years -- for 140 counts of attempted murder -- in addition to his conviction for use of explosives. The judge presiding over the case expressed shock over Holmes' actions.

"It is almost impossible to comprehend how a human being is capable of such acts," Judge Carlos A. Samour Jr. said, at the time.