John Granat plotted with his three friends for months before the Illinois teens brutally beat his parents to death with baseball bats, authorities said Tuesday.

Granat, 17, was charged with first-degree murder on Sept. 13, two days after his parents, John Granat, 44, and Maria Granat, 42, were found bludgeoned to death in their bed.

Investigators started interviewing Christopher Wyma, 17, Mohammad Salahat, 17, and Ehab Qasem, 19, on Oct. 9. The three teens originally claimed they hadn't seen Granat for hours when the slayings occured.

When confronted with evidence contradicting these statements, however, the three quickly gave detailed, video-taped confessions. They then lead investigators to where they had hidden two baseball bats and a knife, bloody clothing, and about $21,000 of the $35,000 authorities say the teens made off with after the killings.

They conspired over the course of months to come up with a plan to kill John Granat's parents and take their money, Cook County Sheriff Tom Dart said. John the son did not like his parents at all, and they also wanted to get some money.

Dart and a prosecutor from the case have since released details of the plot, and how the four allegedly carried the killings out.

The code word was 'concert,' Dart told reporters Oct. 11. And [on the night of the murders] the concert was on.

Dart claims the friends had agreed the plot would be triggered when Ill. teen gave them a single word in an online conversation. The code word was 'concert,' Dart said. And the concert was on.

According to authorities, Granat sent the word concert during an online conversation with the trio, who then joined him at his home. As Salahat stayed in the car, Wyma and Qasem followed Granat into the house, where he gave them baseball bats. The three sneaked into the couple's bedroom, where John and Maria Granat were sleeping, and began hitting the couple with the bats.

At one point, Granat left the bedroom to begin searching for money. His friends soon followed him. The mother [is] still making nosies, Dart reports Qasem told Granat. the boy handed Qasem a knife, the sheriff said. Go upstairs, he instructed, and finish them off.

In a written synopsis of the crime, prosecutors alleged Qasem then went to the mother's body and stabbed her several times before handing the knife to Granat, who stabbed her more than a dozen times.

The three then began ransacking the house. Granat knew his father, who ran a successful contracting business and owned several properties, would have money on hand.

After finding about $35,000 in cash and some jewelry, prosecutors say, they all drove to Wyma's house and divided it up.

It was Granat who made the 911 call from his family home in uncorporated Palos township. He claims he awoke at 7 a.m. and found the family home disturbed. He then found his parents' bodies, ran from home, and called the police.

After authorities found no signs of forced entry, they took a closer look at Granat's story, and found multiple conflicts in his version of events and what the evidence seemed to indicate. Palos Heights police had stopped Granat for a minor traffic offense at 5:17 a.m. at 122nd Street and Harlem Avenue. When police confronted him with the evidence, Granat changed his story, telling investigators he was with Wyma, Salahat and Qasem.

According to prosecutors, several friends of Granat's remember he making multiple threats to kill his parents after they learned he was growing marijuana in their home. One such threat was made immediately after they threw out his stash.

Granat's father had a lacerated kidney, a broken jaw, and had lost most of his teeth. Granat's mother was stabbed 20 times.

Wyma's attorney said outside the courtroom he was not aware of the details of the physical evidence, and questioned investigators' conduct in obtaining the confessions. My client is 17 (and has) a very impressionable mind, John Russell told The Chicago Tribune.

Salahat's attorney, Joel Brodsky, is also skeptical about any statement his client may have made. Brodsky stressed that prosecutors do not allege Salahat took part in the attack, though Dart insists that he was complicit. 

Granat's attorney, meanwhile, said he thinks the three arrests bolster his own contention that Granat is innocent. I told you, Rick Beuke said, [that] if they kept looking they'd find the right killers.

Granat and his three accomplices are charged with first-degree murder. They are denied bail.