Salt Lake County law enforcement agencies plan to form a multi-agency task force Monday to investigate a two-year string of rapes.

Detectives - who are "personally offended" by the attacks -believe at least 19 women and young girls have been raped by the same man since 1989, said Capt. Bill Van Wagenen.

The latest attack occurred last Tuesday afternoon, when an 11-year-old girl allowed a man posing as an automotive service salesman into her apartment, in the area of 700 East and 3900 South.

The man then pulled a knife and raped and sodomized the girl.

"I want you to know what kind of a creep we are dealing with," said Van Wagenen. "We're personally offended. When he starts violating children, all my detectives are very angry. And I am, too."

Van Wagenen said the first case was reported in August 1989 on the west side of Salt Lake County. Since then the attacker has plied his crime with a similar modus operandi throughout the county.

There are nine cases in West Valley City, seven in unincorporated Salt Lake County, two in Murray and one in West Jordan.

Because it is estimated only about 50 percent of all rapes are reported, Van Wagenen is sure the rapist has committed more than 19 assaults.

"If anyone else has been victimized by this guy, we'd really like to hear from them. It might be the link we need to solve (the rapes)."

The captain said the rapist rings the doorbell and represents himself as a salesman selling oil changes and other automotive services.

"He talks to them, through a ruse, into letting him in. And then he pulls a knife and tells them to do as he says or he will kill them."

The rapist initially victimized women but has recently turned to teenage and pre-teen girls, apparently because the women were causing him problems by resisting, Van Wagenen said.

Detectives have released a composite drawing of the man, who is described as Caucasian, 30 t0 35 years old, between 5 feet 10 inches and 6 feet 1 inch tall, between 180 to 220 pounds, with brown eyes, brown hair and a neatly trimmed beard and moustache. In the latest attack, he wore a denim jacket and blue jeans. The weapon was described by victims as a 3-inch pocket knife.

Anyone with any information about the rapes or the suspect is urged to call the sheriff's office, 535-5824.