A former NASA space shuttle commander has been indicted in the deaths of two girls who were killed when his car ploughed into another vehicle.

James Halsell was arrested after the wreck that killed 11-year-old Niomi James and 13-year-old Jayla Parler on a rural Alabama highway on 6 June.

Police reports show investigators believe alcohol and speed could have been factors.

Grand jurors have indicted the 59-year-old on two counts each of reckless murder and assault.

The assault charges stem from injuries suffered by the girls' father, Pernell James of Brent, who was driving, and his friend, Shontel Cutts.


Image: Niomi James (L) and Jayla Parler were ejected from the vehicle by the impact

The former astronaut's lawyers have filed a document arguing the driver of the car carrying the girls was partly to blame because he failed to yield.

The girls' relatives have filed two civil lawsuits blaming Halsell for the deaths.

The girls' father told investigators he was driving about 65 mph on US 82 when a car travelling "at a very high rate of speed" struck his Ford Fiesta from behind.

The impact crushed the Ford and sent it tumbling across the road, according to court documents.

Image: Commander Halsell leads crew members to the launch pad at the Kennedy Space Center in 2000.

The girls, who were not wearing seat belts, were ejected from the vehicle.

A state trooper wrote in a court deposition: "Halsell's speech was slurred, eyes were dilated, clothes dishevelled and he was unstable on his feet and smelled of alcohol."

Police said Halsell, who was driving to his native Louisiana to pick up his son at the time of the crash, is free on bail.

Court documents say authorities did not realise he was a former astronaut until they saw news reports about the case.

Halsell spent more than 1,250 hours in space, serving as commander on three shuttle missions and pilot on two others, according to an online NASA biography.

After the space shuttle Columbia disaster in 2003, Halsell helped lead NASA's return-to-flight effort.

He retired in 2006 and worked for at least two aerospace companies.