Police have reopened an investigation into a five-year-old theft and possible arson now at the center of Saturday's shooting of a New York City plumber and his family at their Montgomery County vacation home.

New information on the victims' finances and statements by Mark Geisenheyner - the man authorities blame for this weekend's attacks - have persuaded investigators to reconsider the 2006 case.

Specifically, they will try to determine if there is any truth to Geisenheyner's claims that he had been a partner in an insurance scam with one of Saturday's victims, 64-year-old Paul Shay.

"We now essentially have multiple reports of multiple incidents of crime," said Douglass Township police Detective Dirk Boughter. "Any time we get new information in an old case, it forces us to reexamine our original conclusions."

A SWAT team killed Geisenheyner, 51, after a seven-hour standoff Monday at a friend's house in Delaware County. Three of his victims - Shay; his wife, Monica; and their nephew Joseph Shay's 37-year-old girlfriend, Kathryn Erdmann - remained hospitalized Wednesday. Joseph Shay and Erdmann's 2-year-old son, Gregory Bosco, died at the scene.

In the 15 months leading up to Saturday's shootings, Geisenheyner told a number of acquaintances that he planned to murder Paul Shay, authorities say.

In a tale Geisenheyner purportedly told over and over, Shay hired him in 2006 to burn down his vacation home on Renninger Road in Douglass - valued at $200,000 - and promised him $300,000 in insurance money.

Instead, Geisenheyner would say, he only received $70,000. On top of that, he was returned to prison for violating parole after police found $222 worth of wildlife prints stolen from the Shay house in his possession.

Geisenheyner was hell-bent on revenge, said Carlton Richardson, 53, of Media, who described himself during an interview Wednesday as the accused killer's best friend.

"He did talk about robbing him to get his money back," said Richardson, referring to conversations in the months after Geisenheyner's 2009 release from prison.

Richardson's recollection matched that of Gary Krobath, whose Trainer home was the site of the shoot-out Monday that left Geisenheyner dead. Krobath, in interviews, has said Geisenheyner told him he intended to kill Shay because the New York man had double-crossed him in the insurance scam.

Douglass police investigated the events surrounding the 2006 fire at the time but only pursued charges on the stolen wildlife prints. Boughter, who originally handled the case, noted Wednesday that several other valuable items were also reported missing. Only the prints were recovered, he said.

Boughter would not describe what other items the Shays reported stolen or their value, citing the ongoing case.

He also declined to discuss whether investigators had considered arson in their probe of the fire but said Geisenheyner's tale of setting the blaze at Shay's request had factored into their decision this week to reopen the case.

Details of the Shays' finances - which emerged in the wake of this weekend's shootings - also contributed to the decision.

According to court records, Shay and his wife owed nearly $27,000 in civil liens obtained by at least four banks and credit card companies in New York City courts in the two years leading up to the fire.

At least two more creditors - seeking more than $14,000 for loan repayments and state taxes - obtained liens between the 2006 blaze and this weekend's shootings.

It was not clear Wednesday whether the couple had paid any of the judgments filed against them.

Investigators have not had an opportunity to fully interview Paul Shay, they said.

Although he is conscious, Shay remains on a breathing tube with limited ability to communicate, said Montgomery County First Assistant District Attorney Kevin Steele.

"We obviously have a lot of questions for him now," Steele said. "We've gotten a few things out of him. But have we really been able to talk to him? Not really."

Contact staff writer Jeremy Roebuck at 267-564-5218, jroebuck@phillynews.com, or @inqmontco on Twitter. Read his blog, "MontCo Memo," at www.philly.com/montcomemo

Inquirer staff writer Anthony R. Wood contributed to this article.