WAIMANALO, Hawaii -- Honolulu police arrested Glenn Keohokapu Jr., 35, in Waimanalo Monday night. He is accused of killing a teenager who tried to break up a fight.

The family of a victim stabbed to death over the weekend said he was acting as a good Samaritan when he was killed.

Honolulu police have a tentative identity on the suspect, but have made no arrests, they said.

Steven Wilcox, 19, was a triplet from Waimanalo. His brothers Shaun and Shane were never far from his side, family members said.

Wilcox was killed early Sunday morning in the parking lot of the Kaneohe Shopping Center strip mall. The victim's mother, Gwen Kalihiwa, said her son was trying to break up a domestic argument when he was stabbed.

"He was a peacemaker -- tried to make things be good, handle things well. That's how I knew my son," Kalihiwa said.

Wilcox's family visited the Kaneohe Fire Station to say thank you to the firefighters who tried to save his life.

Wilcox graduated from Kailua High School, where he played football. His brother Shaun is a pastor at Hope Chapel Waimanalo and remembered the last time he saw Steven alive.

"I elbowed him, and he looked back at me and he smiled, and today I am smiling because I saw him smile," Shaun Wilcox said. "I love him. I miss him."

Wilcox would have celebrated his 20th birthday later this month. Now, his mother is planning his funeral.

The family said they are relying on their faith in God during this tragic time.

"I guarantee he is walking along with Jesus and he is looking down at us saying, 'I got the ticket to heaven before you folks,'" Shaun Wilcox said.