DENVER -- Denver police spokespeople say it simply took time to study recommendations made two years ago to restrict the use of Tasers and hand-held "blackjacks".

Now, use of a Taser is officially prohibited if the suspect could fall and either be seriously injured or killed; if they're driving, holding a handgun, or extremely old, young or physically disabled.

“We’ve been training for this policy before it went live today. We’ve been in training for the last month on this,” said Lt. Dik Kushdilian, spokesman for Denver police.

Officers told TheDenverChannel that the guidelines have either already been in place for years or should be easy to follow.

The "blackjack" or "sap" is now banned.

It's a hand-held weapon, usually less than a foot long and can either be steel or wood, wrapped in leather with a weighted, lead end on one side.

Popular in the 1920s and 30s, Denver was one of the last major American cities to allow them, said Merrick Bobb, Executive Director of the Police Assessment Resource Center in Los Angeles.

Instead, Denver cops will use an extendable, metal baton that makes a significant telescoping sound when readied for use.

“Giving officers the most consistent policies and putting all of these restrictions in one place, these guidelines in one place, makes it easier for them to interpret and do the right thing in every circumstance,” Kushdilian said.