One structure has been damaged in the Tusil Fire, according to Cal Fire. Some evacuation orders and warnings remain in place.
"All three of our victims did not die in vain," San Diego Police Department Chief Scott Wahl said.
Investigators also found 30 guns, ammunition and a crossbow at two homes as they sought to uncover whether the shooters had broader plans.
The Tusil Fire sparked in the 37000 block of Tusil Road on the Campo Reservation, according to Cal Fire.
The arrested group consisted of 16 adults and three unaccompanied children, according to U.S. Customs and Border Protection.
On Tuesday, Islamic community leaders were calling for more security at mosques throughout the country following the attack.
Two teenage gunmen are believed to have killed three people at the Islamic Center of San Diego in a hate-filled killing spree.
Two teenage gunmen are believed to have killed three people at the Islamic Center of San Diego and shot at a landscaper blocks away.
"This is a city and a community's absolute worst nightmare," the police chief said.
Dumpsters, rubbish and one tree were set ablaze before the unidentified suspect was arrested, police said.
The identity of the boy and the cause of his death were not available, police said.
Deputies could not reach the vehicle and called Cal Fire for help.
Enrique Inzunza Cazarez, 53, who is also the former Sinaloa secretary general, could face a maximum sentence of life in prison if convicted.
Take a look at some of this week's police, fire and courtroom stories from across San Diego County.
Hector Amador Balderas, 44, pleaded guilty to hitting Aiden Antonio Torres De Paz with his vehicle.
The fire caused so much damage that the structure was likely to be a complete loss, officials said.
The student had a gun concealed in his pants when he was taken into custody, police said.
Jonclaude Smith failed to yield after an attempted traffic enforcement stop, prompting a vehicle pursuit, sheriff's officials said.
Border Patrol agents have arrested two fugitives wanted in Mexico.
Authorities said Frank Torres, 61, was reported missing Tuesday after family members and friends were unable to find him.
Benito Garcia Jr., 31, was booked into San Diego Central Jail on suspicion of first-degree murder.
The woman was taken to a hospital with a fractured pelvis, police said.
Brandon Ivan Padilla, 20, admitted using a firearm to threaten victims during each crime, according to the U.S. Attorney's Office.
During the checkpoint, officers will look for signs that drivers are under the influence of alcohol or drugs.
Investigators said the man has not been identified because of the extent of his injuries.
Police are seeking additional witnesses.
Police said a speeding car ran a red and hit a marked, on-duty police car.
Betty Broderick, who was convicted of killing her ex-husband and his new wife in 1991, died Friday at a Chino hospital. She was 78.
Authorities boarded eight cruise ships and said they determined that 27 people were involved in the spread of child sexual abuse images.
The victim remains hospitalized in critical condition, police said.
Detectives are working with the Medical Examiner's Office to determine the cause and manner of death.
The lawsuit alleges a deputy responded by driving to the scene, stopping momentarily, then leaving without ever stepping out out of her SUV.
Prosecutors say that in three of the robberies, the perpetrators carjacked the trucks while the drivers were getting gas.
Savannah Monique Taylor, 21, is facing a state prison term of between 7 and 9 years, according to court documents.
The circumstances leading up to the pursuit and shooting were under investigation.
Jose Santana, 36, was arrested Wednesday after a four-day manhunt, according to the San Diego County Sheriff's Office.
Officials said the interdiction was conducted without force.
The signing comes during Missing and Murdered Indigenous People Week, according to the San Diego County Sheriff's Office.
Police are seeking a person of interest in the case.