The Boston police tweet just after 8:30 p.m. Friday was concise: The second suspect in the Boston Marathon bombings was in custody.

Officials, of course, aren’t finished. Next come lots of questions that need answers: Why? How? Are there others?

But the assiduous detective work and perseverance of law enforcement officials makes the next steps possible.

A key move by the FBI was to request help Thursday night from the public in identifying two men seen on security videos at the scene of Monday’s Boston marathon bombings.

The suspects apparently panicked, and in short order a college police officer was killed. Another officer was seriously wounded and one of the suspects died in a dramatic shootout.

Credit the armed, courageous law enforcement officials who were willing to stand in harm’s way. Their bravery recalled that of the first responders in the Marathon bombing, who rushed to the scene instead of fleeing it.

Authorities executed a massive, house-to-house search in the neighborhood of the confrontation. The second suspect was finally found in a boat in the yard of a house.

The suspects were identified as two brothers of Russian Chechen extraction who had lived in the Boston area for a number of years. The elder, who was killed early Friday morning, was 26 years old. The younger, just 19 years old, once served as a lifeguard at the Harvard University indoor swimming pool.

The brothers’ on-line writings suggest that they were Muslims, but reportedly provide no link to the terror bombing.

Despite the drama of the past two days — the horror of the bombing and shootout and deaths as well as the inspirational dedication of first responders, law enforcement and regular people on the street — this story is far from complete.

But for now, the country can take major relief in the quick, professional work of the police and the FBI.