A man is accused of targeting his sister and pregnant niece in a shooting rampage that left two people dead and two wounded, then killing a Florida sheriff's deputy in a shootout, authorities said Friday.

Investigators were still working to determine what led to the shootings, Hernando County sheriff's Sgt. Donna Black said. Deputies say John Kalisz, 55, killed two women — including his older sister — and wounded his pregnant niece and another woman Thursday afternoon at a house near Brooksville, about an hour north of Tampa.

Sheriff's officials say Kalisz left with two loaded shotguns and told his brother by phone that he would kill as many deputies as possible. He then drove north in a white Ford van, engaging deputies in a shootout at a gas station in Cross City, southwest of Gainesville, authorities said.

Dixie County sheriff's Capt. Chad Reed, 33, was killed, and Kalisz was wounded. He remained hospitalized Friday in Gainesville, his condition unknown.

Black said detectives haven't been able to figure out a motive.

"We have not been able to interview the victims," Black said Friday. "We just know it was domestic related."

Killed in Brooksville were Kalisz's sister, 61-year-old Kathryn Donovan, and 59-year-old Deborah Buckley Tillotson.

Wounded were 33-year-old Amy Wilson and Kathryn Donovan's pregnant 18-year-old daughter, Manessa Donovan. Both were in stable condition.

Wilson and Tillotson worked for Kathryn Donovan in her home-based fabrics business.

Kathryn Donovan was an artist and an expert on using color for therapy, longtime friend Kim Wagner told the St. Petersburg Times. Donovan — who went by "Kitty" — had recently published a book, "Understanding Your Color — A Guide to Personal Color Analysis" and provided personal color analysis sessions.

Wagner said Kathryn Donovan had a tense relationship with her brother.

"She was afraid of him and Manessa was afraid of him," she said.

Court records showed Kalisz was on probation for 2009 convictions of contributing to the delinquency of a minor and aggravated assault with a deadly weapon.

Reed, the slain Dixie County deputy, leaves a wife and two young sons. He had previously served as the county's director of emergency management.