"Mr. Johnson did try to evade officers. Mr. Johnson tried to escape officers and he did resist arrest," West Jordan Police Sgt. J.C. Holt said, per the Salt Lake Tribune. "We regret that he made that decision."
Johnson is suspected of the double murder of Tony Butterfield, 31, and his 30-year-old wife Katherine, who were shot dead at their home on Saturday night while their three young children slept.
Neighbors called police after hearing gunshots and screaming at their house; they arrived to find Katherine's body inside, while her husband's was in the yard. Their children, aged four, two and six months, were found upstairs, alive and unharmed.
It is believed the father fought the attacker with a knife, and may have injured him, although investigators would not comment on the possible injuries on Wednesday.
Investigators also understand Johnson knew the couple, and that the crime was not random but targeted, although they would not elaborate on the relationship.
Nor would they be drawn on a motive for the attack; they did however confirm there was evidence of forced entry, and that the house had been rummaged through before the killer fled.
Sgt. Holt confirmed Johnson was "definitely uninvited" and had "criminal intent" on the night of the attack: "Things definitely went very wrong the other night when that happened, unfortunately," he said.
On Monday Johnson's wife, 29-year-old Sina Johnson, was arrested on suspicion of helping her husband escape. She was charged with obstruction of justice and tampering with evidence after admitting she had been in contact with him several times before and after the murders.
Investigators then managed to track him to Sacramento after receiving tips he had friends or family in the area and was driving to them. He will be extradited to Utah in the coming days.
Sgt Holt said the the arrest brought the family "some peace and resolve, but that being said, it's a long road ahead as well. And honestly, it's still just as horrific now, and the shock has still not worn off, I'm sure."
A GoFundMe to help the orphaned siblings has already raised more than $227,000.