(CNN) -- An arrest warrant has been issued for a Florida man suspected in the shooting deaths of four people, including his sisters, in the coastal town of Jupiter, authorities said Saturday.
Paul Michael Merhige, 35, allegedly left the scene of the Thanksgiving Day shooting armed. He faces four counts of first-degree murder and two counts of attempted first-degree murder, the Palm Beach County State Attorney's Office said in a statement.
The U.S. Marshals have joined the search for Merhige, and a $10,000 reward was offered for information leading to his arrest.
The shooting victims include Merhige's 6-year-old cousin, Makayla Sitton; his 33-year-old twin sisters, Carla Merhige and Lisa Knight; and 76-year-old Raymond Joseph, police said.
One of the victims -- Knight -- was pregnant, a police spokeswoman said Friday.
Two others -- Patrick Knight and Clifford Gebara -- were wounded, police said.
Interviews with family members suggest that Merhige "had ongoing resentment" for some of his relatives, said Sally Collins-Ortiz, a spokeswoman for Jupiter police.
The shooting occurred about 10 p.m. Thursday.
Merhige is thought to have escaped in a blue 2007 Toyota Camry with Florida license plate number W42 7JT, police said.