Neighbors say the sound of gunfire was terrifying and unmistakable.
The victims were shot through a side window of the home they shared in Setauket, Long Island at 8:30 Tuesday night.
50-year-old Ross Reisner was struck in the chest and killed.
Friends say his longtime partner, Kevin Murray, was grazed across his arm.
Wednesday night detectives say both were the intended targets of a sniper, lurking in a side yard.
Investigators refused to speculate on a motive or any potential suspects.
But friends tell Eyewitness News that the couple had recently evicted a tenant.
And in recent weeks, Ross Reisner confided that he had been harassed, even threatened.
Reisner was a well-known, well-regarded equestrian. A horse-trainer and a riding instructor who had just opened a horse farm in eastern Long Island.
It is a fast-moving investigation, with several new leads, but so far, no arrests.