Last weekend’s murder of two Black people in Winthrop by a 28-year-old white man, Nathan Allen, has raised a host of questions, including whether the shootings should be characterized as hate crimes. Daniel Medwed, GBH News Legal Analyst and Northeastern University Law Professor, joined Craig LeMoult on Morning Edition to discuss how hate crimes are defined and prosecuted in Massachusetts. This transcript has been edited for clarity and length.

Craig LeMoult: Suffolk County DA Rachael Rollins announced on Sunday that her office is investigating the murders as hate crimes because the police have uncovered several antisemitic and racist writings by the perpetrator. First of all, given that Allen was shot and killed at the scene, what practical purpose does this investigation serve? He can’t be charged posthumously, right?

Daniel Medwed: You’re right — a dead man can’t be charged with a crime, hate or otherwise. But a continued investigation could shed light on several important matters. For one thing, whether other people or organizations may have been involved in planning the attack or fomenting his vitriol and anger, and those organizations could maybe be held accountable in some way. There’s the principle at stake: the need for an accurate accounting, the desire to understand why this happened in order to avoid a recurrence from someone else.

Think about Tamerlan Tsarnaev, one of the Boston marathon bombers in 2013 who died while being apprehended in Watertown and never appeared in court to face the music. His role in the tragedy was a vital piece of his brother’s trial — understanding why he acted in that way was important to grasping why it occurred and helping victims and families obtain closure.

LeMoult: That makes sense. Now let’s pivot to the nuts and bolts of hate crime law. We hear the term “hate crime” a lot, but how is it actually defined in Massachusetts and what do prosecutors need to prove?

Medwed: When it comes to conduct motivated by bias, there are several legal options in the Commonwealth — including civil rights actions that the state Attorney General’s Office could pursue — but the main hate crime law has three parts to it, or what lawyers call “elements:” First, the defendant must have committed something that constitutes a crime, like an assault. Second, that crime must have been committed with the intent to intimidate the individual because they belonged in a particular protected group; and third, the person was chosen because of their race, gender, national origin, religion, sexual orientation, disability or religion. In addition to a fine and/or jail time, the defendant must undergo diversity awareness training and pay a surcharge deposited in a state Diversity Awareness Education Fund.

LeMoult: How difficult is to prove those elements?

Medwed: It depends. It can be relatively easy to show that someone committed a crime, and perhaps also that the victim was chosen because he or she belonged in a protected group. Proving the second element, though — that the crime was committed with the intent to intimidate the person because of their protected status can pose more a challenge. Must the intent to intimidate due to bias be the sole motivating factor in the crime? A substantial factor? Just part of it? The law isn’t crystal clear on that.

A 2015 SJC case, however, Commonwealth v. Kelly, held that prosecutors don’t need to show that bias was the “predominant” or even “substantial factor” in the attack — that the law doesn’t quantify the level of racial animus, just that prosecutors must show it was there. But the ambiguity of the language in our chief hate crime law has caused some problems of interpretation and sparked calls to reform the law.

WATCH: Daniel Medwed on proving a hate crime

LeMoult: What would some of those reform proposals do?

Medwed: Well, one proposal currently floating around the Hill — sponsored among others by a fantastic former law student of mine, state rep Tran Nguyen, I had to put in a plug for her — would clarify some of the language in the law, consolidate the civil rights and criminal remedies into a single, user-friendly piece of legislation, and allow for more severe penalties for certain crimes, especially for repeat offenders. As it stands, the criminal penalties under the hate crime law seem somewhat benign — for instance, a bias-motivated assault that causes bodily injury carries the maximum sentence is just five years.

LeMoult: Well, as usual, you’ve made a complicated legal issue a lot easier to understand. Thank you Daniel.