A Honolulu police officer is in critical condition, after his car was rear-ended in Makaha just before 11:30 last night.  The crash happened on Farrington Highway near Water Street. Witnesses say a Mercedes SUV was speeding north, when it rear-ended the police officer's SUV.  The officer's vehicle flipped over and crashed through a brick wall.  The Mercedes then hit a truck going in the opposite direction.  The officer in his 30s was taken to the hospital in critical condition. The driver of the Mercedes, a 33-year-old man was taken to the hospital in serious condition.  He was arrested for driving under the influence. His passenger, a woman in her 30s, was in serious-to-critical condition. Police believe speed was also a factor in the crash.