A former eastern Missouri sheriff's deputy already facing state sex crime charges is now accused in a federal indictment of sexually abusing four women and enticing a minor into prostitution.

The U.S. Attorney's Office in St. Louis on Friday announced the indictment against Marty Rainey, 52, of Sullivan. He could face up to life in prison if convicted. Attempts to reach Rainey for comment were unsuccessful; his phone number is unlisted and records indicate he does not have an attorney.

Rainey was charged last year in state court with several sex crimes related to the same investigation. A lawsuit filed by one woman alleges she was drugged and sexually assaulted by Rainey, who had sent her sexually suggestive texts after she called asking about a protective order against her estranged husband.

Rainey was a deputy in Gasconade County but also worked at two small police departments, in Hermann and Rosebud. The indictment alleges that between June 2010 and March 2012, he committed aggravated sexual abuse involving four women while serving in his capacity as a law enforcement officer.

The indictment accuses Rainey of enticing a minor under the age of 18 to engage in prostitution in August 2012.

Gasconade County Sheriff Randy Esphorst and Rosebud's police chief were out of the office Friday and unavailable for comment, according to their offices. A message left with the Hermann police chief seeking comment about the allegations also was not immediately returned.

Rainey was charged in January 2015 with several crimes, including acceding to corruption by a public servant, sexual assault, statutory rape and use of a child in a sexual performance. He has pleaded not guilty in the case, though no trial date has been set. His attorney in the state case withdrew as his defense counsel last month; messages left with that attorney were not returned.

The investigation began when a woman told Gasconade County sheriff's investigators that she had sexual relations with Rainey and another man, and Rainey resigned in November 2012. The following year, the sheriff's office received additional complaints from other women who alleged they were sexually abused by Rainey. The investigation widened to include the Missouri State Highway Patrol and the FBI.

The lawsuit filed by one of the woman alleges that Rainey's pursuit of her began in July 2012, when she called the sheriff's office to ask whether a protective order had been served on her estranged husband. Rainey obtained the woman's personal contact information from the call, and over the next few weeks, he called her 87 times and sent 1,288 texts — many of them sexually explicit.

The lawsuit alleges that Rainey picked her up in his patrol car in August 2012, and took her to an Owensville motel where he sexually assaulted her after secretly drugging a drink.

In a yearlong investigation of sexual misconduct by U.S. law enforcement published last year, The Associated Press uncovered about 1,000 officers who lost their badges in a six-year period for rape, sodomy and other sex crimes. However, that number is an undercount because it represents only those officers whose licenses to work in law enforcement were revoked, and not all states take such action.

In January, former Oklahoma City officer Daniel Holtzclaw was sentenced to 263 years in prison for raping and sexually victimizing women on his beat.