Investigators in Florida alerted Michigan authorities to be on the lookout Saturday for a man accused of shooting four relatives to death after a Thanksgiving dinner in South Florida.

The suspect, Paul Michael Merhige, 35, sought a physician in the Detroit area in the past year, Jupiter Police Sgt. Scott Pascarella said, but he was unsure why he needed the doctor.

Merhige is believed to be driving a royal blue 2007 Toyota Camry with a rear spoiler and Florida license plate. He is accused of killing including his pregnant sister and her twin sister, as well as his 6-year-old cousin and 79-year-old aunt.

SLIDESHOW: Thanksgiving Killings

There had been "ongoing resentment" in the family, but investigators weren't sure what specifically prompted Thursday's shooting.

Prosecutors issued an arrest warrant for four counts of first-degree murder and two counts of attempted first-degree murder for Merhige on Saturday night and a $10,000 reward was offered for information leading to his arrest.

Police said Merhige left briefly before returning to the home where 17 relatives had gathered in Jupiter, a small beach town about 90 miles north of Miami. The town is known as a home to celebrities including Michael Jordan and Burt Reynolds.

Pascarella said police first received a 911 call from a neighbor, then another from someone inside the home. The home, in a well-kept new subdivision with brick-paved driveways, is owned by local TV videojournalist Jim Sitton and his wife. The home was surrounded Friday by yellow crime scene tape and police crime unit vans.

Sitton's daughter Makayla had gone to bed before the rampage, police said.

"God packed a lot of sweetness into that little body," Sitton said. "She's just our life. I don't know how we are ever going to recover."

Messages left a phone number listed for Sitton and his wife were not returned Saturday. He told The Palm Beach Post on Saturday that he saw no "red flags" when the two were sitting near each other during Thanksgiving.

Sitton also previously told local media said his daughter was supposed to perform in a holiday production of "The Nutcracker." The Florida Classical Ballet Theatre had two shows Friday.

"Makayla was part of our family, and as one of the youngest dancers, she was to be one of Mother Ginger's Children," artistic director Colleen Smith said. "She was a beautiful, dear girl. She was a beam."

The other victims were Merhige's twin sisters, Carla Merhige and Lisa Knight, and an aunt, Raymonde Joseph. Merhige's brother-in-law Patrick Knight was in critical but stable condition at a local hospital. Another man, Clifford Gebara, 52, was grazed by a bullet.

Carla Merhige was a real estate agent in Miami.

"She was a wonderful agent," said Joanna Sherman, a manager at Coldwell Banker Residential real estate. "She was very active in the community and in charities. She was just a genuine, beautiful individual. She always had a smile for everybody."

Neighbors in the Palm Beach County community were shocked as police processed the home.

"Our kids walk the streets by themselves," said Nicole Kemp, 67, who did not know any of the victims. "I thought it was the safest place to live. I guess it doesn't matter, if there's a maniac here."