John Penkert III, the boyfriend of Donna Hoffmann who was convicted of helping plan the murder of Hoffmann's husband Michael, was sentenced yesterday to life in prison with all but 30 years suspended.

Penkert, 26, of Brandywine, is a construction worker who dated Hoffmann both before and after her marriage to 20-year-old Michael Hoffmann last October.Less than three months after the marriage, Michael Hoffmann was slain on a lonely road in Aquasco in southern Prince George's County and, according to trial testimony, Donna Hoffmann paid $100 to the gunman.

Public Defender James E. Kenkel, Penkert's attorney, described the Dec. 15 slaying as a "crime of passion" in explaining Penkert's role in it following yesterday's sentencing by Judge Jacob Levin.

Penkert, divorced and the father of two children, badgered Donna Hoffmann to go out with him and once even slit his wrists when she would not see him, Hoffmann testified during her trial last week at which she was convicted of murder. A medical report shows that Penkert did attempt to slit his wrists, according to court testimony.

Penkert gave a statement to police saying that Hoffmann asked him to "get rid of" her husband, and he helped plan the slaying with Hoffmann and another friend, Steven Troese, 19, according to prosecutor Michael Whalen. After the murder, according to Whalen, Penkert helped dispose of Hoffmann's body in Black Swamp Creek in Aquasco.

Penkert, who pleaded guilty to conspiracy to committ murder, is one of five young men who entered guilty please in the case and the third to be sentenced. Troese and George Harvey will be to the Patuxent Institution in Jessup, where they will get psychiatric therapy, but Penkert will not get such therapy.

"There is not a real need for psychiatric kelp," said Kenkel. "John Penkert did not lose all his senses to that drug." He was referring to the drug PCP, which, according to the trial testimony, prompted Troese's involvement in the murder.

Penkert will become eligible for parole after six years.