The grandmother of twin 8-year-old boys who was arrested last week on suspicion of murder admitted to shooting both of her grandchildren, according to a court document.

Dorothy Flood, 55, told detectives she shot the boys twice before taking prescription medication in an attempt to kill herself, according to an interim complaint filed by the Pima County Sheriff's Department in Justice Court.

Officials say the boys were found dead Thursday on Tucson's northwest side.

Flood was booked into the Pima County jail Friday on two counts of first-degree murder. She is being held on a $250,000 bond.

About 2 p.m. Thursday, officials with Northwest Fire went to a home in the 2400 block of West Kessler Place, near West Ruthrauff Road and North La Cholla Boulevard, in response to a medical call.

Upon arrival, they found Flood with symptoms of an apparent overdose, according to a news release from the Pima County Sheriff's Department. While providing medical care to her, officials discovered the two children with "obvious signs of trauma," later determined to be gunshot wounds.

The children were pronounced dead at the scene. They have been identified as Jaden and Jordon Webb.