A bogus 911 call that prompted a large law enforcement response in San Marcos and was determined to be a case of "swatting" was traced back to Michigan, the San Diego Sheriff's Department (SDSO) said Thursday.

At least a dozen deputies descended on the San Elijo neighborhood of San Marcos at about 2 p.m. Wednesday after a 911 caller reported that a man had shot his girlfriend and wanted to shoot himself.

Deputies found the person reported as the shooter, who was "shocked" to see law enforcement at his door, SDSO Lt. Eddie Brock said.

It was determined no shots had been fired and no crime had been committed.

Lt. Glenn Giannantonio said the call was a case of swatting, when a caller attempts to get law enforcement to respond to a false emergency.

The call was traced back to an orthodontics office in Michigan that was closed at the time of the incident, Brock said.

It was not clear how many law enforcement officers initially responded to the bogus report, but about 15 San Diego County Sheriff’s (SDSO) deputies with patrol vehicles could be seen on Newschopper 7 gathered at San Elijo Park at about 3:30 p.m.

SDSO said anyone with information on the incident should call Crime Stoppers at (888) 580-8477 and could be eligible for up to a $1,000 reward if information leads to a felony arrest.

Last December, a hoax call about a shooting and kidnapping led to a house where an officer shot and killed a Kansas man.

"Due to the actions of a prankster we have an innocent victim," officers in the case said at the time.

Tyler Barriss, a 25-year-old Los Angeles resident, is facing felony charges in connection.

In 2015, a 15-year-old San Diego student was linked to an online group responsible for swatting calls, SDPD said. The student was arrested after three separate bomb threats against Point Loma High School.