Maria Cristina Gutierrez, a criminal defense lawyer known in Maryland's legal community for her passionate and pugnacious style, died of a heart attack yesterday at St. Joseph Medical Center in Towson. The 52-year-old woman's ailment was exacerbated by multiple sclerosis.

Throughout the 1990s, Ms. Gutierrez argued cases with a tenacity that earned the respect of her peers. Upon graduating from the University of Baltimore School of Law in 1980, she began her career as an assistant public defender in Baltimore.

Ms. Gutierrez, a longtime Baltimore resident, honed her trial skills in that job for several years before going into private practice in the mid-1980s. Known as a skillful communicator before juries, Ms. Gutierrez earned a reputation as a tough foe for prosecutors.

Baltimore Circuit Judge Clifton J. Gordy said that when Ms. Gutierrez was practicing, she would have been the first defense lawyer he would have called if he were charged with a serious crime. "And that's the biggest compliment one lawyer can give another," he said.

Ms. Gutierrez defended Baltimore City Comptroller Jacqueline F. McLean, who eventually pleaded guilty to stealing more than $25,000 from taxpayers.

Other well-known cases included her successful defense of an Anne Arundel schoolteacher accused of having sex with a student; a Howard County mother and son accused of molesting children at their day care center; and two mothers accused of killing their children.

"She wouldn't give up if she thought an injustice was being perpetrated," said Phillip Dantes, a lawyer and friend.

The second of 10 children, Ms. Gutierrez attended Notre Dame Preparatory School, but didn't go to college upon graduation. Instead, she began working in the anti-war, civil rights and labor movements. She eventually finished college at Antioch College in Baltimore in 1976.

But Ms. Gutierrez's ailing health began to affect her career. She had difficulty keeping up with her caseload. Clients complained; a state investigation was launched. Ms. Gutierrez agreed to be disbarred in 2001.

"She just got to the point where she couldn't do it anymore. She was too weak," Mr. Dantes said.

In keeping with her tough-as-nails image, she "wasn't all soft and flowery" in her personal life, her brother, Keith Carlos Gutierrez, said yesterday. "But deep down inside, we knew she loved us, and we loved her. She died in a hospital room, and all of her nine siblings were there, and her parents, too."

Funeral arrangements were pending last night.

Ms. Gutierrez is survived by a son, Roberto Gutierrez; a daughter, Micajaela Orallia Gutierrez; her father, Roberto Gutierrez; her mother, Mary Theresa Gutierrez of Towson; six brothers, Robert Gutierrez of Timonium, David Gutierrez of Salisbury, Richard Gutierrez of Lutherville, Keith Carlos Gutierrez of Towson, and Glen Gutierrez and John Gutierrez, both of Baltimore; and three sisters, Claire Keane of Berlin, Elizabeth Reitz of Towson and Diana Gutierrez of Lutherville; and 19 nieces and nephews.

Sun researcher Paul McCardell contributed to this report.