Charles Medina, 31, was jailed on a manslaughter charge and held on $250,000 bond after authorities said he struck and killed boxer Hannah Rapp while she was cycling in Navasota, Texas, on July 18.
Investigators said Medina sped past Rapp and her boyfriend, then braked, reversed and hit Rapp hard enough to shatter his rear windshield; an affidavit said skid marks and vehicle damage contradicted his claim he was backing up slowly.
The Brazos County sheriff's office said the case remains under investigation and declined to label it road rage, though Texas law allows a 2- to 20-year prison sentence if Medina is convicted.
Rapp, 26, had challenged WBC featherweight champion Tiara Brown on June 13 after building an 8-0-1 start and winning the NABF featherweight title, drawing tributes from boxing, cycling and her hometown of Yorktown, Indiana.
A Change.org petition tied to Medina's prior arrests had gathered more than 3,300 signatures by Tuesday, urging Texas lawmakers to expand judges' power to deny or revoke bond for defendants with violent driving histories.