A terror suspect accused of plotting to blow up the 34th Street subway station at Herald Square wanted only one thing at the time of his arrest: to call his mother. Nineteen months later, a federal judge has ruled that law enforcement officers were not wrong to force Shahawar Matin Siraj to wait to make that call until after they had finished questioning him.

That ruling, released last Wednesday, will allow the government to use as evidence the confession that Mr. Siraj, then 22, made about his alleged role in the thwarted bomb plot.

Judge Nina Gershon of U.S. District Court in Brooklyn ruled that Mr. Siraj’s request to call his mother was not the same as a request to call an attorney. Judge Gershon decided that Mr. Siraj was not coerced into confessing or denied his right to an attorney.

The trial of Mr. Siraj, a Pakistani immigrant who lived in Queens, is scheduled to begin later this month.

In her 15-page ruling, Judge Gershon finds that Mr. Siraj expressed a desire to call his mother to many of the seven law enforcement officers he came in contact with in the hours following his arrest on August 27, 2004. After being questioned by prosecutors for two hours, Mr. Siraj ultimately was allowed to call his mother, Shahina Parveen, who has been present at many of her son’s court appearances.

Lawyers for the defendant had argued that statements by Mr. Siraj should be inadmissible as evidence because Mr. Siraj initially was denied access to a telephone and mistakenly believed that federal prosecutors were in fact his defense attorneys. Earlier this year, Mr. Siraj also testified that he had wanted to contact his parents so that they could call his attorney.

The narrative provided in the court ruling offers a glimpse into how prosecutors interacted with Mr. Siraj in their first contact with him. During his questioning, Mr. Siraj was offered doughnuts, cigarettes, and coffee. At the time, Mr. Siraj was fasting.

“Defendant was eager to talk,and he never told any of the officers present that he wanted a lawyer or that he did not understand his Miranda rights,” Judge Gershon wrote.

His lawyer, Martin Stolar, has said he will argue that Mr. Siraj was never predisposed to violence or militant Islam until a government informant “brainwashed” him.

Mr. Stolar could not be reached for comment yesterday.