(MOSCOW, Idaho) -- University of Idaho student Ethan Chapin was "one of the most incredible people you'll ever know," his mother said before his memorial service.
Chapin, from Conway, Washington, was among four Idaho students stabbed to death in an off-campus house in the early hours of Nov. 13. Chapin didn't live in the house but was sleeping over with his girlfriend, 20-year-old Xana Kernodle, who was also among the victims. No arrests have been made.
Chapin, a triplet, was born right before his sister and brother, who also attend the University of Idaho.
"We're here to honor the life and legacy of our son and brother," his mother, Stacy Chapin, told reporters before Monday's memorial service, with her family standing by her side.
At Idaho, Ethan Chapin was in the Sigma Chi fraternity and was majoring in recreation, sport and tourism management, university president Scott Green said.
The 20-year-old "lived his best life" at college, his obituary said. "He loved the social life, intramurals and tolerated the academics."
He loved sports, from golf to basketball to surfing to pickleball, his family said.
"He laughed continuously. He smiled when he woke up and was still smiling when he went to bed," his obituary said. "He was kind to all and a friend to all."
The murders of Ethan Chapin, Kernodle and two of Kernodle's roommates remain a mystery.
On the night of Nov. 12, Ethan Chapin and Kernodle went to the Sigma Chi house, while the other two victims, Madison Mogen, 21, and Kaylee Goncalves, 21, went to a bar downtown, according to police. All four were home around 1:45 a.m., police said.
Two other roommates -- who survived the attack and are not considered suspects -- also went out that night and returned home by 1 a.m., police said.
It's believed the four students were killed between 3 a.m. and 4 a.m. on Nov. 13, according to Moscow Mayor Art Bettge.
The two surviving roommates were in the basement and slept through the murders, police said. On the morning of Nov. 13, the roommates called friends over to their house because they thought one of the victims on the second floor had passed out and wasn't waking up, police said.
At 11:58 a.m., a 911 call from one of the roommate's phones requested help for an unconscious person, according to police. The 911 caller's identity has not been released but police said "multiple people talked with the 911 dispatcher."
Officers responded and found the four victims on the second and third floors, police said.
Authorities said they do not believe anyone at the house at the time of the 911 call was involved in the murders.
Police urge anyone with information, or anyone who saw anything suspicious on the night of Nov. 12, to call the tip line at 208-883-7180 or send an email to firstname.lastname@example.org.