Suffolk County District Attorney Daniel F. Conley today named Patrick M. Haggan his new first assistant, placing the office’s highly-regarded chief trial counsel in charge of all prosecutions in Boston, Chelsea, Revere, and Winthrop.

“Throughout his career, Pat Haggan has demonstrated all of the qualities and values I hold dear,” Conley said. “He discharges his duties with adherence to the highest level of professional ethics. He is an incredibly hard worker and is always willing to help another with advice and counsel. Pat possesses the legal ability, the talent, and the unerring judgment that the job of first assistant district attorney requires.”

Haggan’s journey from an unpaid law school internship 18 years ago to his appointment today makes him the first prosecutor in Suffolk County history to rise from a district court assignment to being the DA’s second-in-command. As first assistant district attorney, Haggan will oversee about 140 prosecutors who handle upwards of 40,000 cases each year.

“I’m honored, humbled, and privileged to have worked for District Attorney Conley and the people of Suffolk County for so many years,” Haggan said. “I look forward to this new challenge and this new opportunity: an opportunity not only to fight for victims of crime and keep our streets safe, but to do it while cultivating the ideals of fairness, transparency, and professionalism in all our employees on all our cases.”

After impressing his supervisors as a Suffolk University law student allowed to practice under Rule 3:03, Haggan was hired on Jan. 1, 1995, as an assistant district attorney assigned to Dorchester District Court. He went on to be a district court supervisor and, later, a prosecutor in the Major Felony and Homicide units.

“Throughout those years,” Conley said, “Pat has earned the respect and admiration of his colleagues, judges, police investigators, the defense bar, and most importantly the victims and the families he has served.”

The office’s chief trial counsel since 2005, Haggan’s caseload has been notable for complex investigations and high-profile trials – including a six-week, four-defendant murder trial that set a record as the longest trial in modern Suffolk County history. All four defendants were convicted; three were sentenced to life plus 10 years and one was sentenced to double life plus 10.

After their cases were severed, Haggan tried an East Boston man and his girlfriend in back-to-back trials for the 2004 murders of 21-year-old Kayla Ravenell and her 2-year-old son, Xavier. Haggan proved that the defendants – Ravenell’s ex-boyfriend and his new girlfriend – beat and suffocated the victims in a joint venture driven by jealousy and anger over child support payments. Both are now serving double life sentences and their convictions were recently upheld by the state’s highest court.

Haggan tried one pair of murder defendants in four successive trials after two juries declared themselves deadlocked and the sitting judge fell suddenly ill. The first proceedings began in March 2008 and the defendants were not sentenced until June 2009. They are both serving life terms for the murder of 49-year-old Betsy Tripp and the near-fatal shooting of a second victim in a gruesome 2004 home invasion.

In 2007, Haggan was honored with the prestigious Paul McLaughlin Award for a Career Marked by Courage in the Pursuit of Justice. McLaughlin, an assistant attorney general assigned to the Gang Unit of the Suffolk County District Attorney’s Office, was ambushed and shot to death in 1995 by a man he was about to prosecute for carjacking.

Introducing Haggan at that ceremony, Conley read from a letter to the office sent by a woman who had been robbed at gunpoint outside her apartment in 1996 and whose assailant had been prosecuted by Haggan.

“After the incident, I felt alone, anxious, and completely vulnerable,” the woman wrote more than a decade ago. “Now, more than a year later, I can walk the streets of Boston without panicking and looking over my shoulder every minute. I owe each and every one of those steps to Assistant District Attorney Patrick Haggan.”

Haggan takes over for Conley’s previous first assistant, Josh Wall, who departed to oversee the Massachusetts Parole Board. He is a graduate of Boston College and Suffolk University School of Law. He lives with his wife, Lynn, and two children.