Police arrested a 43-year-old man after he allegedly attacked a 74-year-old man in the Mokuleia area on New Year’s Day.

Police said the suspect assaulted the victim with an unspecified dangerous instrument shortly after 3:35 a.m. Tuesday.

The assailant is described as the ex-boyfriend of the victim’s daughter.

Police said the victim sustained lacerations to his torso and arm and was taken to a trauma hospital in serious condition.

Police arrested the suspect at about 4:20 a.m. in the area of Waialua Beach Road and Komo Street on suspicion of second-degree attempted murder.