Jennifer Soules, and Ken Alltucker

A 24-year-old Flagstaff police officer with less than one year on the job was shot in the face and killed by a 28-year-old man who then turned the gun on himself, police said.

Officer Tyler Stewart encountered a suspect at a home in the 800 block of West Clay Avenue during an investigation of an earlier domestic-violence call, spokeswoman Sgt. Margaret Bentzen said. Robert W. Smith of Prescott, fired several shots at Stewart, who was outside his patrol car, police said. Smith then shot himself dead, according to police.

Additional officers were dispatched after several residents in the area reported Stewart lying on the ground and when dispatchers could no longer get a verbal reply from him, Bentzen said.

He was rushed to Flagstaff Medical Center, where he was pronounced dead.

"This is an enormous tragedy for our department and the family of our officer," Flagstaff Police Chief Kevin Treadway said in a statement. "We are a very close-knit organization, and know that all members of the Flagstaff Police Department are grieving at this time. With that being said, all of the men and women of the Flagstaff Police Department extend our prayers and condolences to the family of our Officer Tyler Stewart."

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Mayor Jerry Nabours described that shooting as "heartbreaking" to the police department, Officer Stewart's family and the Flagstaff community.

Officer Stewart comes from a family of law enforcement. His father, Frank Stewart, is a sergeant at the Department of Public Safety. He could not be reached for comments at this time.

The police department will sponsor a candlelight vigil at 5:30 p.m. today at the Officer Down Memorial Statue, located in front of the Flagstaff Police Department headquarters, 911 E. Sawmill Road. Another vigil is planned in Anthem at 5:30 p.m. today, at the Anthem Community Park, located at 41703 N. Gavilan Peak Parkway. Stewart's family is expected to attend the Flagstaff vigil, Bentzen said. Cards, flowers and candles left by well wishers began piling up at the memorial Saturday evening.

Stewart is the second Flagstaff police officer to be killed in the line of duty. The first was Officer Jeff Moritz who was shot and killed June 21, 2000.

Nabours said the shooting punctuates the dangerous job that police officers face each day, particularly with cases involving domestic violence.

"It is a dangerous job from day one," Nabours said. "In Flagstaff, we very much know and like our police officers. They may very well be your child's little league coach, somebody you went to high school with, so we think of our police as part of the community and our friends."

The news of the shooting quickly rippled through law-enforcement circles, family, friends and elected officials, with Gov. Jan Brewer ordering Arizona flags at half-staff until this evening.

Jimmy Chavez, President of the Arizona Highway Patrol Association, said he was driving home from Colorado when he was besieged with messages from the law-enforcement community.

Chavez said domestic-violence calls are among the most dangerous for responding officers. He said officers are typically advised to wait for backup during such scenarios, but he did not know the circumstances involving Officer Stewart.

"Those are never safe scenarios to go into in any event," Chavez said.

Levi Bolton, executive director of the Arizona Police Association, said his organization would reach out to the Flagstaff officers and others to provide any support that his organization is able.

"He carried a badge and made the ultimate sacrifice," Bolton said.

Stewart was a 2008 graduate of Boulder Creek High School in Anthem. He later graduated from Concordia College in California.

High-school friend Dylan Frusco played basketball with Stewart during their freshman year and described his friend as one of the happiest people someone could meet.

"[Tyler was] always positive; he was probably one of the nicest kids I've ever met," Frusco said.

Frusco only played basketball with Stewart for one year, but said he remembered seeing Stewart's father at almost every game. Frusco went on to attribute a large part of Stewart's personality to his father, but said he had since lost touch with the family.

"We'd lost touch, but that doesn't take the shock away," Frusco said.

Kathy Pondy teaches American government at Boulder Creek High School. Stewart was in her class during his senior year of high school.

Pondy described Stewart as "just a good kid" who always contributed in class.

His former teacher said she was not at all surprised that Stewart chose a career in law enforcement.

"Being a bigger piece of a community was important to him," Pondy said. "I think that's why he went into law enforcement; that sense of community…he always wanted to protect a group whether it was his teammates, his community or his classmates.

"I am so thankful for Tyler and honored to have been his teacher."

Several friends also mourned Stewart's passing on the social-media website Facebook, with some posting pictures, sharing memories or turning their Facebook user profiles black with a thin blue line.

Flagstaff resident Gabriel Sedillo was driving to store Saturday afternoon just after 1:30 p.m. when he heard several police cars with sirens blaring. He immediately turned around to make sure there wasn't a fire in his neighborhood, but what he found was much worse than he expected.

He met a neighborhood friend who lives near the house where the shooting occurred. Then he saw emergency workers escorting out a body.

"When I got there, there were a couple of officers carting a body. I can't say whether he was dead or alive," Sedillo said. "It seemed like they were trying to resuscitate him."

Sedillo said he was inside his neighbor's house attempting to comfort her when he saw one of the shooter's roommates, who also went to the neighbor's house following the shooting. Police officers then asked Sedillo and his friend to leave the area so they could question the shooter's roommate, Sedillo said.

Sedillo said he then drove the neighbor and family members to a nearby bookstore before returning home, where he could not shake the grisly scene he had just witnessed.

"I hope I never see that again," Sedillo said.