A Baltimore courier has been charged with four rapes and an attempted rape in a series of attacks on women during May and June in Sligo Creek Park and in Bethesda and Burtonsville, police said yesterday.

The arrest of Tony M. Chatman, 28, followed the formation of a 42-member task force of Montgomery County and Maryland-National Capital Park Police, which sent plainclothes officers jogging and bicycling in the park in search of a man matching the descriptions given by victims and witnesses.

Chatman, who is being held without bail, was initially arrested July 1 after a Silver Spring dentist told police that a courier from a Baltimore dental lab matched the description given by a woman assaulted at knifepoint near his office on University Boulevard.

Last week, Chatman was charged with the additional rapes after a police lineup involving victims and witnesses to the other assaults, according to Officer Timothy Boyle of the Park Police.

All five attacks involved young women, who were assaulted in daylight hours by a man who in most cases grabbed them by the throat.

"All of the descriptions of the assailant in these cases, with some slight deviations among them, matched that of Chatman," said Detective Lauren Acquaviva of the Montgomery County police in Bethesda.

If convicted, Chatman could face a maximum sentence of life in prison for each rape charge and a 15-year sentence for the assault charge, according to the state's attorney's office.

The first of the cases involved a 26-year-old woman sunbathing in Sligo Creek Park south of Dennis Avenue on May 6. The man sat on a picnic table doing exercises before approaching the woman and then dragging her into some bushes where he raped her, police said.

Then on May 15, a 16-year-old girl was raped while walking from Paint Branch High School to Rte. 29 late in the afternoon. The rapist was armed with a knife, Acquaviva said.

On the afternoon of June 12, a 32-year-old woman was studying in her car in Sligo Creek Park between University Boulevard and Dennis Avenue. The woman was grabbed by the throat, pulled into the back seat of her car and raped, police said.

The fourth rape victim was a 23-year-old woman who was walking in the rain in Bethesda when she was attacked on June 22. That was followed by an attempted assault on June 30 on Sligo Creek Parkway south of Wayne Avenue, in which a 25-year-old woman was jogging when a man ran up behind her, grabbed her by the throat and tried to drag her into some bushes, Acquaviva said. He said that the attacker fled when the woman's screams alerted a passer-by.