Nathen Taylor Dead: Former Army Sergeant Shot Outside Brother's Home (VIDEO)

A Lancaster, Calif. family is in mourning over the loss of Nathen Taylor, a former Army sergeant who survived three tours in Iraq and Afghanistan, only to be shot to death in his hometown.

Taylor, 30, was shot Saturday while sitting in a car outside his brother's home. He was still alive when his brother, Patrick Taylor, and family friend, Jack Garcia, called for an ambulance. Patrick claimed that the ambulance took 30 minutes to arrive, reports CBS2/KCAL9, and Garcia decried emergency services for taking such a long time to arrive.

Garcia told CBS2/KCAL9, "If I'd have known -- his car was still running -- I would have moved him over and drove him to the hospital myself. That's what I should have done. But I had faith in the system, and I don't anymore."

WATCH CBS2/KCAL9's report from the scene of the crime:

On Monday, Taylor's family members and friends were gathered near a makeshift memorial at the scene of his death.

Sister Kinnzie Taylor, still in shock, told NBC LA that the circumstances of his death were unbelievable. "To serve three different tours overseas in a war zone, and to come home and be killed in your -- not just your neighborhood, but a neighborhood we grew up in..."

Nathen Taylor left behind a 7-year-old daughter and a fiancee.

WATCH NBC LA's video report from Nathen Taylor's makeshift memorial:

View more videos at: http://nbclosangeles.com.

The shooter -- and cause of the shooting -- remain unknown.

Anyone with information about this incident is encouraged to contact the Los Angeles County Sheriff's Department Homicide Bureau at (323) 890-5500. To give anonymous tips, call "Crime Stoppers" at (800) 222-TIPS (8477), or text the letters TIPLA plus your tip to CRIMES (274637), or by using the website lacrimestoppers.org.