With the Twin Cities Marathon just three weeks away, Boston Police Superintendent William Evans met with local law enforcement officials Thursday to share the hard lessons learned from the April 15 Boston Marathon bombing.

Intense preparation and vigilance during the race itself are everything, he said at the event in Bloomington.

"You can't do enough training," he said, along with, "You can never let your guard down."

Organizers of the Oct. 6 run, officially called the Medtronic Twin Cities Marathon, said that they're always reviewing security, and that runners and spectators won't see many signs that it's been enhanced, because most of the measures Evans described are in place.

"We're already doing the things we should," said Virginia Brophy Achman, executive director of Twin Cities in Motion, which organizes several races through the year, including the marathon and 10-mile race the same day. More than 12,000 runners are expected to participate in this year's marathon, with even more people lining the 26.2-mile route.

One difference this year: Spectators are asked to leave backpacks and purses at home because such items can arouse suspicion and concern. If large packs are brought to the race area, police will ask those carrying them to consent to searches.

Two bombs placed in backpacks and allegedly left near the Boston finish line by two brothers exploded, killing three spectators and injuring 264 people. Police and rescue personnel responded swiftly, Evans said; the scene was cleared of the injured within 22 minutes, and no one who went to a hospital died.

Authorities' response to the event was largely praised as prompt, smooth and effective, but there were lessons, he said.

Security to be tight and broad

In the Twin Cities, runners start near the Metrodome, wend around the lakes, up the west and east Mississippi River parkways, down St. Paul's Summit Avenue and end at the State Capitol, where the biggest crowds gather.

Because the marathon starts in Minneapolis and ends in St. Paul, police from both cities are involved, as well as Hennepin and Ramsey county sheriffs' offices, state and federal law enforcement, Brophy Achman said, adding, "We rely on their expertise."

She called the law enforcement presence along the route "significant," but declined to provide numbers or to confirm the presence of undercover officers, saying she had been asked not to divulge the information.

Evans endorsed the plan to search backpacks and large bags brought to the area. The fewer bags around, the better, because it's "very difficult" to notice someone dropping a bag in a crowd, which is what the Boston bombers did, he said.

Another concern at marathons has been the bags that runners are given to carry clothing, food and water to the start line, then check and leave with volunteers to be transported and picked up after the finish. Some marathons have considered dropping the practice or switching to clear bags. The Twin Cities race has always issued clear plastic bags to runners so the contents are visible, Brophy Achman said.

She and Evans emphasized that volunteers, spectators and runners should actively participate in security.

"In general, for everybody as you go about your daily life, if you see something that isn't right, you should say something," Brophy Achman said.

Evans used similar words when he spoke to reporters before his closed-door afternoon session with hundreds of law enforcement officers.

The long marathon route is a difficult distance to protect and is known as a soft target. "All you can do is ask the public, if they see something, say something," he said.

Evans himself ran the marathon in Boston and had finished when the bombs went off. He was one of three officers who arrested the second suspect under the overturned boat in a yard in Watertown, Mass.

He spoke of one major miscalculation: Boston organizers had calculated that any attack was most likely to occur at the finish as the elite runners were crossing the line — not two hours later, when the four-hour runners were coming in.

Evans wouldn't share all of the advice he planned to share with law enforcement officers, but he did describe one critical concern: Cellphone call capacity was overloaded in the hours after the Boston bombings, so police couldn't use them to make calls.

"If you have a major incident, cellphones are useless," Evans said. Officers were able to send text messages and took over a hotel floor to borrow hard lines.

Law enforcement is prepared for that grim possibility, having found alternatives to cellphones in the event of an emergency at the Twin Cities Marathon, Brophy Achman said. "That's all I can say," she said.

Saying no to fear

Evans said he intends to run again next spring in Boston. "If you're intimidated, you're giving in to what terrorists want," he said.

He was invited to town by the Minnesota Chiefs of Police Foundation, a charitable organization focused on training officers. Evans isn't on a talk circuit and wasn't paid a speaker's fee, but his travel expenses were covered.

Asked to comment on the Twin Cities Marathon's self-billing as "the most beautiful urban marathon in America," Evans said, "I think I'd like to run it."