Deputy Constable Paul Armand was making what he thought was a routine traffic stop early Tuesday morning when he pulled over a car that didn't have headlights on.

As he approached the black Mazda 626, the Precinct 8 deputy noticed the driver had blood on his face. He also saw that the front windshield was shattered and partially inside the vehicle.

The deputy constable then saw a body in the passenger seat, partially underneath the dashboard and with a severed leg.

"He (Armand) was shocked," said Precinct 8 Capt. Jason Finnen.

The driver, James John Onak, 45, told the deputy he didn't realize a dead body was in the passenger seat, Finnen said.

Police allege Onak struck 32-year-old Fadel Steadman with his car on the Gulf Freeway in southeast Houston and kept on driving for three miles while the man's body lay in his passenger seat.

Onak was later arrested and charged with felony failure to stop and render aid involving a fatality and driving while intoxicated.

Houston police, who took over the investigation, estimate that the accident occurred in the southbound lanes of the 12200 block of Gulf Freeway around 12:30 a.m. Tuesday, about 10 minutes before Armand pulled Onak over.

Investigators believe Steadman had pulled his Ford Explorer into the emergency lane on the left side of the freeway near Fuqua after the vehicle broke down.

Witnesses told police Steadman was running back and forth across the freeway when he was struck by the Mazda.

The collision forced Steadman's body through the windshield, and he landed in the front passenger seat inside the car, police said.

However, Onak did not stop driving. Police said he got off the freeway and drove a few more blocks before he was pulled over by Armand on Kirkvalley near Beamer, police said.

Onak told Armand he thought he had hit something while driving down the Gulf Freeway, but he was not sure, Finnen said.

After discovering the body in the seat, Armand called paramedics and additional deputy constables to the scene. While searching the freeway, another deputy constable located the Mazda's licence plate as well as what appeared to be Steadman's leg, Finnen said.

In 2001, a Fort Worth woman, who after a night of drinking and using drugs, struck a homeless man with her car and drove home with the man crumpled in the windshield. She then left him in her garage where he died two days later. The woman, Chante Mallard, was convicted and sentenced to 50 years in prison in 2003.

Onak, who is jailed in lieu of a $55,500 bail, faces two to 10 years in prison as well as up to a $10,000 fine for the felony charge.

He is scheduled to appear in court Thursday.

Chronicle reporter Dale Lezon contributed to this report.

anita.hassan@chron.com