The suspects were offered 400,000 Dominican pesos — about $7,800 — to shoot the 43-year-old, Dominican National Police Director Ney Aldrin Bautista Almonte said.
Authorities have six people in custody, and one remained at large Wednesday, Bautista Almonte said.
Ortiz, who is also known as Big Papi, was at a nightclub in Santo Domingo on Sunday night along with television host Jhoel Lopez when they were both injured by gunfire.
The bullet struck Ortiz in the back and went through his stomach, police said.
Authorities have declined to discuss a possible motive.
“These individuals, each one of them, all of them, have been jailed and will go before a court,” Bautista Almonte said.
Shooter’s weapon recovered
Eddy Vladimir Féliz Garcia, accused of driving the shooter to the club on the back of a motorcycle, was the first to be arrested. He has been charged with being an accomplice to attempted murder.
Investigators spoke with Féliz Garcia at a local hospital and were then able to locate the other five suspects now in custody.
Deivi Solano, one of Féliz Garcia’s attorneys, said his client is a motorcycle taxi driver and may have unwittingly driven the shooter, but he did not shoot Ortiz.
A witness told police he saw Féliz García and the gunman get into a car that was parked near the scene of the shooting before gunfire erupted, the charging documents say.
It is unclear what charges each of the suspects face, but investigators are treating the case as an attempted murder.
Investigators recovered the gunman’s firearm buried in the home of one of the suspects in the province of Mao, police said.
Big Papi recovers in Boston
Shortly after the shooting, Ortiz was rushed to a local hospital and was in the intensive care unit after being treated for bleeding in his liver and having portions of his intestines and gall bladder removed, said Leo Lopez, his spokesman.
But the next day, the Red Sox sent a plane to have him flown to Boston.
He is now recovering in the intensive care unit at Massachusetts General Hospital after his second surgery, said his wife, Tiffany Ortiz.
“Yesterday and this morning, David was able to sit up as well as take some steps,” Tiffany Ortiz said Wednesday. “His condition is guarded and he will remain in the ICU for the coming days, but he is making good progress towards recovery.”
CNN’s Nicole Chavez, Jeffery York, Amir Vera and Eliott C. McLaughlin contributed to this report.