In online chat, Munck told girlfriend he killed his brother, tried to keep it a secret

In an online conversation, Shawn J. Munck told an out-of-state girlfriend that he killed his 12-year-old brother and didn't know what to do, detectives said.

In the conversation on the social networking Web site MySpace, Munck asked the girl for help, saying his brother was lying in bed deceased. "He's definitely stone cold dead," Shawn Munck wrote.

The conversation shows that Munck, 22, knew he had caused the death of Peter J. Munck and was actively trying to keep it a secret, said Broome County Sheriff's Detective Lt. Patrick Isenburg, who discussed the conversation with the Press & Sun-Bulletin on Friday.

"It certainly shows he was fully aware of what had taken place," Isenburg said of the Internet chat.

Isenburg also sought to dispel claims that the boy's death resulted from "horseplay." Isenburg said what Shawn Munck did to cause his brother's death went well beyond brotherly horseplay.

In the online conversation that took place Feb. 14 -- almost two days after Peter Munck died and more than 24 hours before his body was found by a relative -- Shawn Munck told the girl he choked his brother during a fight on the night of Feb. 12, just hours before he died, according to Isenburg.

He wrote that he got angry with his brother for tearing some photos, including one of the girlfriend.

Isenburg said Munck told the girl he put Peter in a "sleeper hold" until the boy passed out. Peter woke up a minute later, Shawn said, then passed out again while watching television.

When Peter again woke up, Shawn Munck carried the boy to bed, and told him to get some sleep, according Isenburg's account of the online chat.

"It's kind of chilling when you take a look and realize he carried him to bed," Isenburg said.

However, Peter did not show any signs of having been choked, Isenburg said.

Despite Shawn Munck's revelations, the girl did not call police, Isenburg said.

Detectives did not identify the girlfriend, except to say she lives out of state. She and Munck never met in person, but talked regularly on the phone and over the Internet, Isenburg said.

The chat also shows that Shawn Munck knew the boy was lying in bed deceased and spent three days pretending he was alive so a friend wouldn't be suspicious, Isenburg said. Munck told the girl he would go into Peter's room to act like he was checking on his brother.

Munck was afraid his friend, Joe Menard, 23, would discover that Peter had died, Isenburg said.

Both Shawn Munck and Menard were in and out of the house regularly in the days following Peter's death, said Isenburg.

Menard, Shawn Munck's friend who was in the home when Peter was injured, has said Shawn and Peter were just "horsing around."

But based on the severity of Peter's injuries, police believe that Shawn Munck used his foot to exert extreme pressure on the boy's midsection, causing injuries that led to his death several hours later. An autopsy conducted at Lourdes Hospital in Binghamton revealed that Peter died of internal bleeding.

Detectives have called the incident that led to Peter's death a "physical altercation." It is not known if immediate medical treatment could have saved Peter. "He certainly stood a better chance than when he was there being left in bed," Isenburg said.

Detectives began an investigation after a relative discovered Peter's body the night of Feb. 15 and called police. During questioning, Shawn Munck gave investigators his MySpace account information.

Detectives discovered the chat on Feb. 16. He hadn't yet been charged in the boy's death.

Shawn signed the bottom of a chat transcript, confirming the messages to the girl were from him, Isenburg said.

Meanwhile, Shawn Munck remains in Broome County Jail, charged with second-degree manslaughter, a felony.