A Holladay man has been arrested and accused of setting an Orem house on fire with people still inside.

No one was injured in the incident. Daniel Richard Johnson, 41, was booked into the Utah County Jail for investigation of two counts of attempted murder and aggravated arson.

The arrest comes just two days after Johnson's family sent letters to a judge pleading for court-ordered long-term mental health treatment and expressing concerns that he may hurt himself and be an "unintentional but real danger to others."

About 4 a.m. Wednesday, emergency crews were called to a house fire at 951 E. 1050 North in Orem. The garage was destroyed and "most of the roof structure was consumed and burnt," according to a police booking affidavit.

Two people were in the home at the time of the fire.

"The adult male homeowner was sleeping on the main level of the home, and his granddaughter, 18, was in the basement. The granddaughter heard noises and smelled gas, and exited the home through a basement window well. She then alerted and awoke her grandfather on the main level of the home with the help of first responders who had arrived. Both occupants of the home escaped without injury," the affidavit states.

Investigators from the Orem Fire Department, Unified Fire Authority and the state were called to help determine how the fire started, "and investigators soon confirmed the belief that the call was arson," according to the affidavit.

Four newer-looking gas cans were found on the lawn and an accelerant was detected in multiple areas around the home, according to investigators.

"Multiple ignition points were visible where it appeared that fires had been started on and around the exterior of the home," the affidavit states.

After talking with the homeowner, police identified Johnson as a person of interest in the case.

"In recent days, leading up to the date of this arson, Daniel had threatened harm to the homeowner via text messages, and had also talked to the homeowner and others about fires, and fires being started. Fire emojis had also been sent via text. It was also relayed to detectives that Daniel may suffer from some mental illness," the affidavit states.

Police have not said how Johnson and the homeowner are acquainted with each other.

After additional evidence was collected, Unified police assisted in taking Johnson into custody in Salt Lake County. He was not questioned at that time, "but made utterances, on his own, that he had caused this fire," the affidavit alleges.

When Orem police took him into their custody and questioned him, they said Johnson admitted purchasing gas cans and gas.

"He stated that he asked for a ride to the incident location and was dropped off, and that he dumped the gas all around the home, and lit it on fire with a lighter. He gave various explanations of why he started the fire. He admitted that he was OK if harm came to the homeowner … but he stated he had tried to wake other females that he believed were inside the home by knocking on the outside windows," according to the affidavit.

In December, Johnson was convicted of criminal mischief. On Monday, as part of that case, Johnson's sister and father submitted letters to the judge asking for help for Johnson who they say has a long history of mental illness and has been diagnosed with schizophrenia and bipolar disorder and has hallucinations, according to court records.

The sister requested that the judge move his case into mental health court or order Johnson to undergo psychiatric and drug treatment, court records indicate. She says her brother has not been able to get an appointment to see a professional for help because no appointments are available. Both the sister and father pleaded for Johnson to get long-term help rather than the continuous cycle of being arrested and released after a short stay in a pyschiatric ward.