SANTA ROSA (CBS SF) — A Colorado man who burst into his estranged family’s Santa Rosa home and opened fire last week, killing one man and wounding his son and four-year-old grandson has died from a self-inflicted wound, authorities said.

The Santa Rosa Police Department said Walter Ross died on Saturday night from a self-inflicted head wound nearly a week after he entered the home armed with loaded 9mm semi-automatic handgun, a .357 revolver and five explosive devices.

Detectives, who traveled to Ross’ hometown of Colorado Springs to further investigate the shooting, also released new information on the June 24th rampage inside a home on the 400 block of Garfield Park Ave.

The investigators uncovered evidence which suggests that Ross carried out a meticulous and premeditated attack with the intentions of taking the lives of his estranged wife, his adult son, who lived in Santa Rosa, and his son’s immediate family.

The evidence shows that Ross planned to take his own life at the conclusion of his act of violence.

The investigation revealed that Ross parked his vehicle near his son’s residence. He then rigged his parked vehicle with an improvised explosive device which would have caused death or serious injury to anyone who opened the unlocked driver’s side door of the vehicle.

An alert police officer located the vehicle and observed the device before opening the door.

Ross approached his son’s residence with a loaded 9mm semi-automatic handgun and .357 revolver. He was also carrying a bag which contained five improvised explosive devices.

When he attempted to enter the residence, Ross was delayed by the heroic actions of Tim Gillaspie. Ross fired multiple rounds at Gillaspie, fatally wounding him.

But the brief delay gave the seven others inside the residence time to begin to flee the residence. One additional victim hid in the bathtub in a bathroom inside the residence in fear of her life. She called 911 to report the shooting.

After Ross forcefully entered the residence, he began firing multiple gunshots as the occupants fled the house in terror. The rounds fired by Ross, struck his adult son twice in the leg and his four-year-old grandson once in the head.

Fortunately, the wounds were not serious and they have been released from the hospital and are recovering.

Ross fired in excess of 15 rounds from a combination of the two handguns. Santa Rosa Police Officers arrived on the scene within minutes, and as they walked up the driveway toward the home they heard one gunshot.

It appears that Ross saw the approaching police officers and shot himself in the head in an effort to take his own life.

Ross was still alive when the SWAT team members entered the residence. He was transported to a local hospital to receive medical care, but never regained consciousness and was never able to provide a statement to the investigators.

On Saturday evening, he passed away as a result of his self-inflicted gunshot wound.