GILBERTSVILLE, Pa. (CBSNewYork/AP) — A New York City resident and a 2-year-old boy were shot execution-style in a rural home in suburban Philadelphia. Two other New Yorker were among three other people critically injured in the shooting.

Now police are investigating the death of the suspected shooter. Pennsylvania police surrounded a house in a neighboring county and, after a neary six-hour standoff, shot and killed suspected gunman Mark Geisenheyner, they said, as he pointed a gun at them, reports CBS 2’s Pablo Guzman.

Authorities believe Geisenheyner went to the home to rob it, our colleagues at reported.

The incident started late Saturday when police were called to the residence in Douglass Township in Montgomery County, about 30 miles northwest of Philadelphia.

“What we’ve learned through the investigation is that, for the past 15 months or so, Mark Geisenheyner had been planning to break into this home, to steal and to kill Paul Shay,” Montgomery County District Attorney Risa Vetri Ferman said.

Police said they believe that Geisenheyner and Paul Shay had been involved in some kind of insurance scam that resulted in Geisenheyner, but not Paul Shay, going to prison in 2006.

Authorities said Geisenheyner came out for revenge against Shay, but that there were other people in the house.

“We understand that he was surprised by the number of individuals there,” Ferman said. “Still, we believe, he took those shots in any case, and then escaped from the residence.”

First Assistant District Attorney Kevin R. Steele identified the dead Sunday as 43-year-old Joseph Shay, of New York City and Yarmouth, Mass., and 2-year-old Gregory Erdmann, of Fall River, Mass.

The boy’s mother, 37-year-old Kathryn Erdmann, was shot in the head and is listed in critical condition. Also critically injured were the homeowners, 64-year-old Paul Shay and 58-year-old Monica Shay, of New York City.

The Shays live in the East Village. Paul Shay owns a plumbing company. Monica Shay works at the Pratt Institute.

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