CAMBRIDGE, Mass. — A temporary memorial has been unveiled in honor of the Massachusetts Institute of Technology police officer who authorities say was killed by the Boston Marathon bombing suspects.

The granite memorial for Sean Collier was dedicated Friday during a ceremony on campus attended by about 200 people.

Authorities allege the bombing suspects shot and killed Collier on April 18 to get his gun as they tried to make their escape.

MIT Police Chief John DiFava said time tends to make people forget about tragedies such as Collier’s death, but “support for Sean seems to grow every day.”

Friday’s ceremony took place six months to the day after Collier’s death. A candlelight vigil is scheduled for 10:20 p.m., the exact time he was slain.

A permanent memorial will be erected in the future.