GRAND RAPIDS, Mich. (AP) _ A high school teacher had time to reflect on his actions before inflicting the final, fatal stab wounds on a prostitute, the prosecutor said.

A Kent County Circuit jury on Thursday afternoon deliberated three hours before adjourning on the fate of Richard A. Jensen Jr., who is charged with stabbing Kerry Mansfield 55 times in a church parking lot on March 17. The jury resumed deliberations this morning.

Jensen, who taught at Ottawa Hills High School for 22 years up until his arrest, also is a suspect in two assaults on prostitutes earlier this year and in two slayings last year.

In addition to first-degree murder, the jury received instructions on possible verdicts of second-degree murder and manslaughter and an acquittal on Jensen's plea of self-defense.

Jensen's attorney, Thomas Rizzo, acknowledges that Jensen killed Mansfield, 23, after picking her up on a street corner. But he contends Mansfield threatened him with a knife she found in his car.

Jensen, 44, told police in a taped confession that Mansfield grabbed the 7- inch knife after he changed his mind about having sex and told her to get out of his car. Tests showed cocaine in her system when she died.

''He thought he was going to be killed that night. He acted accordingly and snapped,'' Rizzo told the jury. ''It was pure, unadulterated fear for his life.''

Judge Dennis Leiber prohibited Rizzo from using a planned defense of diminished mental capacity in his closing arguments, saying no supporting evidence had been presented.

Prosecutor Steven Dunker argued that Jensen not only knew what he was doing, but had time before the fatal chest wounds were administered to spare Mansfield's life.

Dunker contended that after Jensen stabbed Mansfield in the back 28 times, he dragged her body to a darker spot of the parking lot, then stabbed her 20 more times in the chest after seeing that she was still breathing. At that time, according to the medical examiner, Mansfield would have already been paralyzed from the neck down because her spinal cord had been severed.

''Twenty-eight stab wounds in the back. Self-defense?'' Dunker said. ''He deliberated and he premeditated those last 20 blows to the chest and those are the wounds that make Mr. Jensen guilty of murder in the first degree.''

Dunker had called more than a dozen witnesses, including two women who witnessed the slaying from their window and took down Jensen's license plate number before he fled. Rizzo called just one witness, a toxicologist who testified that the cocaine in Mansfield's system would have made her dangerous.

Mansfield, who had given birth just 19 days earlier, was trying to earn money to buy crack, according to testimony.