According to Sgt. Dugan with TPD, a call came in just before 5 p.m. and the caller hung up the phone before saying anything to dispatch.
Officers then received a second 911 call and the caller said that a man with blood on this clothes was in front of the house screaming for help. The caller said the man was saying someone has just killed his mother in a residence down the street,
When officers arrived at the home in the 6000 block of E. 20th St., they met with a neighbor who said a family member from the home went to their house for help. The family member told police when he entered the home he saw one of his family members deceased in the front room of the house.
Sgt. Dugan says while officers were outside they heard gunshots. TPD then evacuated several homes in the area.
Hostage negotiators were also on the scene.
After not being able to make contact with anyone inside, bomb squad robots were used and were able to locate three people dead inside.
Detectives with the Tucson Police Homicide Unit and Aggravated Assault Unit were able to piece together that Rusty had murdered his wife, Willa, earlier that day inside the home. Officials say she was found in the back bedroom with obvious signs of trauma.
Detectives say that at approximately 3 p.m. Matthew Johnson, Willa's son, came home and was shot multiple times by Rusty in the living room. Just after 4 p.m., Matthew's twin brother came home and was confronted by Rusty at gunpoint.
Officials say it appears that Rusty tried to shoot Matthew's brother, but his gun malfunctioned, then Rusty forced him into a back bedroom where he got a second gun that also malfunctioned.
Matthew's brother was able to escape from the home and ran to a neighbors house where he yelled for help. He had a laceration on his head and several abrasions.
Detectives believe the gunshot heard by responding officers was from Rusty Coblyn taking his own life.
This investigation is ongoing.
Stay with KGUN9 and KGUN9.com for more on this developing story.