Investigators say he was the uncle of the two young children who died and the brother-in-law to their mother who was badly injured.
Police say he set the fire "to kill everyone in the home."
Fresno Police have identified the man accused of intentionally starting a deadly house fire in west central Fresno Tuesday as 29-year-old Filimon "Robert" Hurtado.
The suspect was living at the home with his brother, sister-in-law, niece and nephew.
#BREAKING @FresnoPolice have announced the arrest of Filimon "Robert" Hurtado, 29, for the arson fire that left an 18-month-old and 5-month-old dead and their mother severely injured. Investigators say the suspect admitted he "wanted to kill everyone in the home." @ABC30 pic.twitter.com/5YDf3moJ1a— Jessica Harrington (@JessicaABC30) May 4, 2022
"In this case, there really is no rhyme or reason for him to do something in such a horrendous manner, didn't provide an explanation for us," said Fresno Police Department Lt. Paul Cervantes.
Officials say the suspect made admissions about the fire to paramedics and firefighters. That's when officers were called in.
Fresno Police say they believe the 32-year-old mother was awake at the time and Hurtado used gasoline to start the fire.
"The mother came to the doorway and encountered the brother-in-law, Filimon "Robert" Hurtado and then at some point in time thereafter, she was lit on fire and then she left the residence," Lt. Cervantes said.
She ran across the street to alert a neighbor to call 911 and the fire ultimately reached the room where she and her two young children were staying.
A memorial has been set up at the home in west central Fresno where 18-month-old Cataleya Hurtado and 5-month-old Calyx Hurtado were killed in a fire yesterday. Investigators say their uncle intentionally set the fire. @ABC30 pic.twitter.com/nHfCAWiEgx— Jessica Harrington (@JessicaABC30) May 4, 2022
Outside of the home Wednesday, a memorial was set up for the suspect's niece, 18-month-old Cataleya and nephew, 5-month-old Calyx.
The father of the children, the suspect's brother, had left for work before the fire started.
Investigators say Hurtado did not have a criminal history and officers had not been previously called to the home.
Detectives are still trying to determine a motive and are hoping the 32-year-old mother will pull through.
"We hope that the mother is able to recover from this incident, but I can tell you it's going to be a long process for her," Lt. Cervantes said.
Officials say the suspect had substantial burns and is being treated at the hospital.
Once he is released, he will be booked into the Fresno County Jail for two counts of murder, attempted murder and arson-related crimes.