(Reuters) - Authorities have raised the reward to $20,000 for information leading to the arrest of a man accused in the 2014 murder of a member of the prominent Halliburton family, who escaped from a Florida courthouse during a proceeding on Friday.

Officials are searching for Dayonte Resiles, who fled from the courthouse in Fort Lauderdale at about 9:30 a.m. and was last seen wearing a white T-shirt and black shorts, the Broward Sheriff's Office said.

Resiles is charged with the September 2014 home invasion stabbing death of Jill Halliburton Su, 59, in nearby Davie. She was a member of the wealthy Texas-based Halliburton Co family, who was married to a University of Florida entomology professor.

Resiles, 21, had been brought from a jail to the courthouse and was seated in a jury box with other inmates when he suddenly leapt out of the box and toward the door, Sheriff Scott Israel said.

Two bailiffs, described by Israel as unarmed citizens, were in the room at the time, but were unable to detain Resiles. He left behind his shackles and slipped out of his jail-issued jumpsuit as he ran, Israel said.

Local media reports said Resiles was in the courthouse for a hearing on a defense motion to remove the death penalty as a sentencing option. The reports said police dogs sniffed the jumpsuit to obtain a scent before being employed to track Resiles.

Broward Sheriff's Office spokeswoman Joy Oglesby said on Saturday that authorities believe Resiles is armed and dangerous and also think his escape was planned and that he received assistance.

A nationwide alert warning about Resiles has been sent to the public, but authorities are still focusing their search within the tri-county area, Oglesby said. The initial reward offered was $10,000.

(Reporting by Curtis Skinner in San Francisco; Editing by Matthew Lewis)