PHOENIX -- Police have arrested a woman for allegedly shooting and killing her husband at their central Phoenix home.
That murder investigation kept detectives at the home all night.
Officers were called to the home of Donald Mellon Jr. and his wife, Rebekah, near Central Avenue and Encanto Boulevard just after 10 p.m. Tuesday.
"They found Mr. Mellon with obvious trauma," said Officer James Holmes of the Phoenix Police Department.
Mellon Jr., whose father owns at least two Valley McDonald's restaurants, was rushed a local hospital. Doctors pronounced him dead a short time later.
"Officers attempted to speak with Rebekah Mellon to determine what had occurred in the home, but she became uncooperative with police and she was subsequently detained until the arrival of detectives," Holmes said in a news release.
After hours of gathering and analyzing evidence, detectives developed probable cause to arrest Rebekah in connection with the murder of her 46-year-old husband.
Investigators are still piecing everything together so they are not release much in the way of details, saying only that Mellon was shot to death and they believe Rebekah Mellon pulled the trigger. They do not, however, know what happened in the minutes and hours leading up to that.
"We have information that leads us to believe that she's the one who inflicted that gunshot wound," Holmes said nearly 12 hours after the shooting. "Our detectives are still working hard because now we have to figure out why."
Rebekah Mellon's 11-year-old son reportedly was on the scene with police Wednesday morning, but investigators said he was not home when his mom allegedly shot and killed Donald Mellon Jr.
Holmes said Rebekah Mellon will be booked on suspicion of first-degree murder later in the day.
According to the Arizona Revised Statutes, a classification of first-degree murder, a class 1 felony, means investigators believe there was premeditation and intention.
In the meantime, the investigation into Mellon's death and his wife's suspected involvement is ongoing.