The trail of evidence led them to a family recently in the news for collecting a huge settlement from the city of Fresno for the death of a teenager at the hands of police.
"Clearly, this family has been seasoned in this type of behavior," said Fresno County District Attorney Lisa Smittcamp.
KFSN-TV has uncovered evidence that detectives prevented another murder while they made the case against a familiar family, but the case may be more complicated.
Christina Lopez kept a low profile as she sued the city of Fresno over the police shooting and killing her 16-year-old son Isiah Murrietta-Golding as he ran away from officers trying to detain or arrest him.
The case settled before trial this April for $4.9 million.
Smittcamp says Lopez has spent at least some of her money on criminal activity.
"She has continued now to take the money from her settlement that she received from the city of Fresno to buy a home where she lives in addition to spending thousands of dollars on guns that she has in turn given to her 14-year-old son," she said.
Lopez now faces 22 counts of gun trafficking.
Prosecutors say she bought guns and gave them to that son to distribute to gang members.
But Lopez's attorney says she can account for all the money she got from the settlement.
He says she moved out of the Calwa area to get her remaining kids away from any trouble, and providing guns to gangs would be out of character.
"We have to see what they have and what type of concrete, physical evidence that we can look at so that would connect her," said defense attorney Ralph Torres.
The Fresno County sheriff's investigation leading to Lopez started with the murder of Javier Fernandez in Malaga in July and then Adrian Gamboa in Fresno last month.
KFSN uncovered court documents detailing how wiretaps picked up another murder plot involving Jessie Aguilar, a gang shot caller who's already in prison for a 2014 murder.
"Especially troublesome, Aguilar was directing teenagers belonging to the gang to commit murders," said Fresno County Sheriff Margaret Mims.
In the documents, investigators say Aguilar told Juan Alfredo Venegas who to kill over Gamboa's murder, and Venegas recruited Lopez's 14-year-old son to help.
They arranged to meet the victim at Calwa Park, but Fresno County sheriff's detectives prevented the murder and arrested Venegas with a gun converted to be a machine gun.
Legal analyst Tony Capozzi says it'll be hard for a defense attorney to deny the wiretap evidence.
"That's very substantial, strong evidence as to what they were talking about obviously," Capozzi said. "But then, did they follow up and do something? Yes they did. One of them was at the park and found by the police, arrested, and what he said on the phone was found in his car."
Detectives arrested Richard Aguilar, who's not related to Jessie, for the murder of Javier Fernandez.
They have not arrested anyone for Gamboa's murder.
Christina Lopez is in jail for now and makes her first court appearance on Tuesday.