N.J. MURDER DEFENDANT SURRENDERS

Author: RON AVERY and SUSAN BENNETT, Daily News Staff Writers

Murder defendant Mimi Rohrer, who'd been sought on an arrest warrant after failing to appear at her trial yesterday and today, surrendered herself to a Philadelphia policeman this afternoon.

The woman, who's charged with killing her 2-year-old adopted son in 1975, walked up to a police officer at Broad and Arch streets shortly before 2 p.m. and identified herself.

She surrendered as a hearing on her competency was getting under way. Rohrer's lawyer, Raymond M. Brown, had asked New Jersey Superior Court Judge David Eynon for the hearing.

It was not immediately disclosed if Rohrer's 12-year-old daughter, whom she had taken with her, was still with her when she surrendered.

Brown - whom Rohrer sought to fire last week - also filed a motion today concerning his representation of Rohrer. He would not give any details on the contents of the motion, on which a ruling is pending.

Rohrer, 43, the wife of Haddon Township mayor and prominent banker William G. Rohrer, is charged with the beating death of her 2-year-old adopted son in 1975. A warrant for her arrest was issued after she failed to appear in Superior Court at 9 a.m. yesterday.

The judge revealed today that Rohrer herself, acting without her attorney, had caused two petitions to be filed yesterday. The petitions were brought to court and filed by an unidentified man.

One petition requested a stay of Eynon's refusal to let Mimi Rohrer fire Brown. The other asked that the trial be halted until an appellate court could hear certain issues, which Eynon did not identify.

Eynon denied both petitions.

The jury, which is not sequestered, was dismissed for the second day in a row without an explanation of the delay.

Rohrer's husband said in a telephone interview that he last saw his wife about 1 a.m. yesterday, when she awakened him to say she was not feeling well.

Rohrer said he told his wife it was too late to see a doctor and went back to sleep. When he woke again about 8 a.m., Rohrer said, his wife and their adopted daughter, Laura, were missing.

Mrs. Rohrer reportedly was seen in Washington, D.C., where she first visited the congressional office of Democratic vice presidential candidate Geraldine Ferraro and later the Walter Mondale-Ferraro campaign headquarters.

Deputy State Attorney General Anthony Zarrillo, who is prosecuting the case, said Eynon received a late morning call from an aide at Ferraro's congressional office saying Mrs. Rohrer had been there and left some material.

Zarrillo said the Ferraro aide told Eynon the woman appeared shortly before noon and left some papers that she said would help Mondale's campaign and ''harm the Republicans." Before leaving Ferraro's office in the House Office Building, the aide said, Mrs. Rohrer told staff members she was going to Mondale-Ferraro campaign headquarters. The aide said after Mrs. Rohrer left, Ferraro's staff looked at the papers, realized who she was and called to notify the judge.

At Mondale-Ferraro headquarters yesterday, Mrs. Rohrer was met in the lobby where she asked a staff member to photocopy some papers she had brought with her, a campaign aide said. He said a member of the campaign staff told her that could not be done and Mrs. Rohrer left without leaving any papers.

Zarrillo said an arrest warrant for Rohrer was telexed to Washington, but police there apparently missed the woman.

John "Jack" Corrigan, deputy campaign director for the Mondale-Ferraro campaign, said Ferraro's congressional staff called him yesterday about Rohrer's visit to Ferraro's Capitol Hill office.

Corrigan said a Ferraro aide told Rohrer to ask for Corrigan when she arrived at Mondale-Ferraro headquarters. About 30 minutes later, Corrigan said Eynon called and "explained the situation."

"I asked the front desk to notify me as soon as she showed and to be nice to her," Corrigan said. "But the next thing I knew, the stuff had already been dropped off."

Corrigan said Rohrer left a motion and affidavit in support of the motion. He gave no further details.

Rohrer, a Republican leader in Camden County, speculated that his wife went to Ferraro's congressional office and the Mondale-Ferraro headquarters to hurt him "because I'm a Republican." But he would not elaborate on why his wife would want to hurt him politically or otherwise.

Rohrer said his wife had been particularly upset during the past four days - the trial was in recess from Friday until yesterday.

"She wanted to get through the trial and get it over," he said. "All she could do was sit around and think about it, and that's worse than being there. There's no one to discuss it with. And she's been upset by the newspaper coverage."

Mrs. Rohrer has met with the judge behind closed doors several times during the trial to express dissatisfaction with Brown, the son of Raymond A. Brown, one of New Jersey's most experienced trial lawyers.

At times, she met with other lawyers during breaks in the trial, and she recently hired a secretary to take shorthand notes of testimony.

Rohrer said he doesn't know why his wife is so disturbed by Brown's handling of the case. "It's just a feeling that she has."

He said they had expected the senior Brown to handle the defense, but he recently underwent surgery and could not come to court.

Rohrer said he is paying the younger Brown more than $250,000 to represent his wife.

Mrs. Rohrer is charged with murder in the death of William Rohrer III, whom the couple adopted along with Laura on a trip to El Salvador in 1975. Both orphans were about 2 1/2 years old at the time of the adoption.

Three months after the Rohrers returned with the children to New Jersey, the boy died of head injuries.

Child abuse was suspected because bruises were found all over the boy's body. However, Camden County investigators accepted Mrs. Rohrer's story that the child threw violent temper fits and the injuries were self-inflicted.

In 1977, the State Commission of Investigations looked into the death and concluded the first investigation had been botched and the case should be reopened. She was subsequently indicted by a state grand jury.

Laura has continued to live with the couple, and yesterday, Rohrer said he was glad his wife took Laura with her, indicating he did not fear for the child's safety.