Marine Pfc. Robert R. Garwood, the only American veteran convicted for collaboration with the enemy in Vietnam, goes on trial today on charges of sexually molesting a 7-year-old girl.

Garwood could be sentenced to life in prison on charges of committing a first-degree sex offense, attempted first-degree rape and taking indecent liberties. He has pleaded innocent.

Garwood's trial deepens the legal quagmire that has plagued him since his return to the United States after nearly 14 years behind enemy lines in Vietnam.

Almost two weeks after Garwood's conviction by a military jury Feb. 10, a grand jury indicted him on charges stemming from all alleged incident Aug. 7, 1980, when he was taking the child home from a church function at her parent's request.

The government has said very little about its case, and defense attorneys complain privately that they know little about the specific charges against Garwood.

Judge Robert Rouse last week denied Garwood's lawyers permission to question the alleged victim and another girl considered a potential witness. Rouse ruled that North Carolina law does not require prosecution witnesses to submit to questioning before their testimony.

After the civilian trial, Garwood's attorneys will be back in military court to appeal his conviction and try to obtain $147,000 in back pay and benefits Garwood claims he is owed for his years behind enemy lines.