The Mastic Beach man who police say killed his wife before turning the gun on himself Thursday was being investigated for possible involvement in a fatal shooting last November, a source with knowledge of the case said.

At the time of the suspected murder-suicide, Wayne Street, 29, was on probation for a weapons charge, court records show.

"In light of this heartbreaking tragedy, it would be wrong to speculate whether Mr. Street was the focus of a murder investigation," Anthony LaPinta of Hauppauge, Street's attorney, said Friday in a statement.

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Suffolk police said Street shot his wife, Jenni Lee Street, 28, inside their rented Woodside Drive home before killing himself. Two of their six children, a toddler and a newborn, were in the house, police said.

When the other children returned from school about 4:40 p.m. and found the door locked, they told an adult who called 911, police said. Detectives have not offered a motive in the killings.

Street had been questioned by police but not arrested in the slaying of 51-year-old Terrance Scott in Mastic on Nov. 29, 2014, the source said.

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Police said Scott and another person were inside a home about 4:15 a.m. when an unknown man entered and shot the victim. Scott was taken to a hospital where he later died.

Records show Street also had a prior misdemeanor conviction for a 2009 assault. The weapons charge involved a baton found in his car.

But LaPinta said the couple "by all accounts had a very good relationship, and this [murder-suicide] is something that was out of leftfield."

Bryan Lubitz, who coached one of the couple's sons, said the Streets attended every Police Athletic League football practice and game. "They were just always upbeat and very positive," he said. The Streets had two of their children together and the others from previous relationships, Lubitz said. Jenni Lee Street worked as a nurse at Southampton Hospital, Lubitz said.If the couple had problems, "they definitely didn't lead on to let anyone know," he said. "There were no signs at all -- I wish that there were."

LaPinta said Wayne Street had been on disability for a shoulder injury.

The William Floyd School District said grief counselors were made available for students Friday and will be provided through next week.

"Our thoughts and prayers are with the children and surviving members of the family at this time," the district said in a statement.