When Richard Cole was arrested in a gambling raid three years ago, Prince George's County police took $15,500 away from him along with other items they said were evidence of an illegal sports betting operation.

Charges against Cole, a 46-year-old auto salesman, were dropped last year, and now he wants his money back.

The county refuses to surrender it to Cole, even though a judge has ruled that it sould. The judge's ruling is being appealed, and the county takes the position that "the money is guilty even if the person is not," according to Associate County Attorney Steven Gilbert.

"How can the money be guilty?" complains Cole. "I thought you were innocent before you were proved guilty . . . It's ridiculous. They have no right to hold my money."

County police seize many thousands of dollars each year in the course of gambling raids and, after the defendants are convicted, the money -- sometimes totaling $100,000 in a year -- is forfeited to the county treasury.

"We look on this as free tax money," said one county official. "It's taxing the criminal element."

Cole and more than two-dozen other persons were arrested Oct. 31, 1977, in a series of raids that county police said was one of the largest in county history. Police claimed they had broken up a $500,000-a-week Washington area sports betting operation. Those arrested included prominent local businessmen, an attorney and a junior high school teacher.

Much of the evidence that police gathered resulted from court-ordered wiretaps, since investigators said betting transactions were handled over the phone.

But the wiretap, requested by Prince George's State's Attorney Arthur A. Marshall while he was vacationing outside the county, was later declared to be illegal.

A judge ruled that the wiretap request -- signed by Marshall in a motel in Ocean City, Md. -- violated procedural requirments since it was prepared outside the 7th Judicial Circuit.

As a result, evidence gathered in the case was suppressed and prosecutors dropped charges against most of the defendants, although at least one conviction was obtained in a case in which the defendant had already pleaded guilty.

Cole was no longer accused of illegal gambling, but he did not have the $15,500.

Most of the sum, he says, was won lawfully at a race track and some belongs to a friend. Cole says that he and his two children can not afford to lose any of the portion that belongs to him.

He went back to court several weeks ago and got Circuit Court Judge Jacob S. Levin to rule that the county must pay him back the $15,500.

County attorneys said they are using the Cole case to challenge a state law that says there must be a conviction before money confiscated by police in gambling cases can be kept by the government.

"We're not going to roll over and play dead," said County Attorney Robert Ostrom, who is taking the case to the Maryland Court of Special Appeals.