WEST VALLEY CITY -- About 10,000 people are expected at a funeral Friday for a Draper police sergeant gunned down last weekend in the line of duty by a transient man who also shot himself and his girlfriend.
The funeral for Sgt. Derek Johnson, 32, is scheduled to begin at 11 a.m. at the Maverick Center in West Valley City, a suburb of Salt Lake City.
Following a two-hour service, there will be a motorcade procession with hundreds of police cars and fire trucks to escort Johnson's body to a burial site in Sandy.
Police believe Timothy Walker, 35, killed Johnson early Sunday after the sergeant stopped to investigate a Volvo parked oddly along a road. The full details of what happened have yet to be released publicly, but police have said that Johnson was ambushed, shot while in the seat of his patrol car before it crashed into a tree.
Charges have not yet been filed against Walker, who was upgraded on Thursday to serious from critical condition.
His longtime girlfriend, Traci Vaillancourt, 34, is in fair condition and has spoken with investigators. Based on those conversations, investigators still believe she is a victim, Unified Police spokesman Justin Hoyal said.
Vaillancourt's sister said earlier this week that the couple showed up at her house the day before the shooting looking for money and behaving strangely. Vicki King said Walker was showing off weapons, and talking very fast. The couple had been living in motels for years and recently camped in the Volvo, she said.
They had a 5-year-old daughter together that is in permanent custody of her grandmother.
Walker owes more than $42,000 in child support payments and was at risk of being jailed for it, court records show. His only criminal violation in Utah was a disorderly conduct conviction in 2000.
Court records show Vaillancourt pleaded guilty to theft charges in 2003 -- the most serious charge in a criminal record littered with traffic violations and debt. She was most recently charged with retail theft on Aug. 20 in South Jordan.
The focus Friday, however, will be on Johnson who leaves behind a wife and young son.
Friends and family say Johnson always wanted to be a police officer and loved being a public servant. He became a full-time officer in Draper in 2004 and was promoted to sergeant in 2012.
Johnson was the first officer killed in the 11-year history of the Draper police department. Draper is a city of 44,000 about 15 miles south of Salt Lake City.
He is the first Utah law enforcement officer killed since Utah Highway Patrol Trooper Aaron Beesley died in June 2012 after falling from a cliff during a search and rescue mission near Mount Olympus. The last officer gunned down was Ogden Officer Jared Francom, who was shot during a drug raid in January 2012.