RANCONIA, N.H. — A cousin of skiing star Bode Miller fatally shot and ran over a police officer, then was killed by a passer-by who grabbed the officer's gun.

Liko Kenney shot Cpl. Bruce McKay four times and ran over him after a traffic stop Friday evening, state Attorney General Kelly Ayotte said. Gregory Floyd, who was driving by with his son, grabbed McKay''s gun and shot Kenney when he refused to put his gun down, Ayotte said.

The 24-year-old Kenney was convicted of assaulting McKay and resisting arrest in 2003. Ayotte had no other details of that previous incident between the men, and rejected suggestions the officer should have let someone else handle the traffic stop given his history with the driver.

Officials said McKay pulled Kenney over for speeding on Route 116. Kenney took off, and McKay

The officer used pepper spray on Kenney and his passenger and then turned around and was shot, Ayotte said Saturday at a news conference in Concord. Soon after, Floyd arrived and confronted Kenney while his son called for help using the officer''s radio. Authorities said Floyd was justified in shooting Kenney.

The 48-year-old McKay was a 12-year veteran of the Franconia Police Department.