Honolulu police arrested a 32-year-old man after he allegedly struck a security guard with a metal water container at Fort Street Mall Tuesday.
The attack occurred at about 5:25 p.m.
Police said the guard, 57, told him to get off the property at which time the suspect hit the guard, with the water bottle, rendering the victim unconscious.
The guard sustained a head injury and was taken in critical condition to a hospital.
Officers located the suspect nearby and arrested him on suspicion of second-degree attempted murder, three counts of criminal contempt of court and two counts of probation revocation.
He has a criminal history that includes four felony drug-related convictions, one misdemeanor criminal trespassing conviction and three petty misdemeanor theft convictions.
Police said the suspect remains in custody as of this morning.