Peoria police said a 16-year-old boy accused of beating and stabbing a man to death did not act alone. Police now believe the victim's wife and son plotted to kill him.
According to police records, 39-year-old Steven Gibson's murder was planned by his wife, Michelle Gibson, 41, and teenage son, Steven Gibson Jr., 16, at least a week in advance of his March 1 death.
On Monday, Peoria police said three arrests have been in his murder and three other people have been identified as being involved but have not been charged yet.
Steven Gibson was found dead in the garage of his Peoria home during the early morning hours.
Erik McBee, 16, returned to the home when police were investigating and he confessed to killing him. McBee was charged as an adult with first-degree murder.
On Friday, police announced that detectives learned McBee did not act alone.
According to the police report, the day before the murder, McBee met with Steven Gibson Jr., and a 16-year-old boy and 14-year-old girl to talk with Michelle Gibson about killing her husband. Michelle Gibson alleged that they needed to kill him before he killed her or her son.
Michelle Gibson gave the 16-year-old boy a five-shot revolver handgun and told him to use it to kill her husband, according to police. The plan involved subduing her husband with chloroform and then loading him in his own truck, driving him to a nearby park and shooting him in the head near a bridge. Police said the plan also entailed scattering pills on the body to make it look like a drug deal gone bad. Michelle Gibson and her son told the accomplices that the body needed to be found so a money inheritance could be paid out.
The mother-son duo offered the 16-year-old boy and McBee $2,000 to split once he was dead. The 16-year-old's mom, unaware of the plot, called and told him she was going to pick him up. He did not return to the home, according to police.
Michelle Gibson and her daughter left the home about 10:30 p.m. and while they were gone, McBee hit Steven Gibson in the head three times with a baseball bat while he was asleep in bed. Police said McBee beat Steven Gibson again with the bat while he was down on the bathroom floor. Police said after talking with McBee by phone, they believe Steven Gibson, Jr., was dropped off at the home by his mother and helped kill his father by stabbing him three times with a knife and slitting his throat.
Police believe McBee, Steven Gibson Jr. and the 14-year-old girl moved the body onto a metal box dolly. They heard sirens while attempting to put the body in the truck and McBee and the girl took off on foot.
Police said Steven Gibson Jr. tried to clean up the home and hide evidence and when his mother returned she also helped get rid of evidence. She then called police to make it appear as though Steven Gibson was found murdered in the garage.
Michelle Gibson claimed her son was with her that night while she was shopping, but surveillance video and cell phone records don't show that. Police said Michelle Gibson stated in an interview that she likes to play "Marco Polo" with the cell phones sometimes while they shop.
On March 28, Michelle Gibson was arrested and she was taken to the police station where she requested an attorney, according to police records.
When Michelle Gibson's 17-year-old daughter was interviewed, she said her brother told her that he was the one who stabbed their father.
Michelle Gibson is now facing one count of conspiracy in first-degree murder, conspiracy and hindering prosecution.
Peoria police said Steven Gibson Jr. was arrested on March 27 and is being charged as an adult on first-degree murder and conspiracy charges.
McBee pleaded not guilty to first-degree murder charges and his next court date will be April 29, 2013.
The teenage girl with McBee was interviewed and released and has not been charged at this time, according to Peoria police, and neither has the 16-year-old boy who Michelle Gibson allegedly offered to hire in the murder plot.
Stay with cbs5az.com for updates on this developing story.
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